Relay/s, Voltage Drop/s, Current Flow, Grounds and ... more

[SS402]

A relay is nothing more than a device that uses a low-current signal to operate a high-current circuit, he solenoid on your starter is a type of relay that uses the low-current signal from your starter switch to operate the high-current circuit between the battery and the starter motor. High-current circuits create heat, enough heat to melt plastic components and weld contacts together, we don't want that kind of heat behind the dash so we use low-current switches and relay's to operate the high-current circuits that abound on a automobile. From the horn to the headlights to the wipers to the blower motor, all these circuits and more require relays to operate them otherwise we would need to run heavy gauge wiring throughout the vehicle and this would only add weight to an already overweight object, not to mention oversized and bulky switches to handle the current flow.
A lot of older vehicles and their components suffer from Voltage drop, voltage drop occurs when the circuit can't transmit the source voltage to the load, if we follow Ohm's law we disover that if a circuit has constant resistance value and we reduce the Input voltage that the current increases proportionally, current equals heat and that heat destroys component/s and sometimes the circuit itself. The problem lies in the dashboard itself as most of the circuits to operate the various functions have to travel through the printed circuit traces and other connections, every connection in a circuit is a potential area for a voltage drop. You can measure voltage drop by using a voltmeter at the source and then measuring voltage at the load, you may be surprised to find that the headligts are only getting 10VDC but there appear to be 12Volt at the switch, this indicates a 2Volt voltage drop between the switch and the headlights themselves.
To cure the Voltage drop and get full power to the circuit all we need to do is use the signal wire from the switch which normally ran directly to the headlight/s through the dashboard wiring and connect 9t to the signal terminal on a suitable relay, then connect the headlight circuit to the switched output of the relay terminal, then run a heavy gauge wire to supply power to the high-current input terminal of the relay. Now, when we flip the headlight switch all we are doing is activating the high-current switch aka relay and allowing it to transfer it to transfer all available voltage from the source to the load thus eliminating the potentil for a electrical fire in the process by minimizing current flow through the switch itself and it's nominal wiring.
Current flows from Positive to Negative through the battery but flows from Negative to Positive through the circuit, so current leaves the battery on the Negative side, travels through the circuit and back to the Positive terminal. Lot's of inexperienced tech's fail to realize the importance of the ground circuit and focus on the positive side when the ground circuit is equally as important as current flow starts there, a bad ground can also cause a voltage drop and is usually the reason for a component such as the headlights, horn or wipers failing to operate correctly, we can miminize the chance of a bad ground by making sure all connections are clean and making solid metal to metal contact. Also be sure ther is a suitable body ground connecting the chassis to the frame since the frame sits on rubber mounts, the main ground on most GM products is usually bolted to the painted alternator bracket and the painted bracket is bolted to the painted cylinder head and/or block, simply relocating the main ground to a spot on the block can alleviate most if not all of the voltage drop in that circuit, bolting the cable to the head is nice but the head is resting on a non-conductive gasket and electrically connected to the block with head-bolts and since the head-bolt holes are not blind they extend into the water jacket thus making the possibilty of the rust between the bolt and the block itself more likely
Every conductive material has a specific resistance, some conductors have more specific resistance than others and vice versa, the key is to minimize resistance through a circuit so current flows uninhibited by paint, rust or other types of corrosion, sometimes i don't know when to quit but hopefully you have a better understanding and are now armed with the knowledge to correct these factory imperfections operate your vehicle with peace of mind and less chance of electrical fire/s.
http://www.helminc.com/helm
http://www.factoryrepairmanuals.com...ice-manual-2-volume-set-original-shop-repair/
your working at a huge dis-advantage if you don,t have a factory shop manual for your specific year car, and basic tools like a multi-meter, and vacuum /pressure gauge

http://www.harborfreight.com/fuel-injection-pump-tester-92699.html

http://garage.grumpysperformance.co...urrent-flow-grounds-and-more.3504/#post-54625

http://garage.grumpysperformance.co...hooting-tip-for-electronics.11317/#post-51557

https://www.the12volt.com/relays/relaydiagrams.asp (read)

http://www.harborfreight.com/5-in-1-dig ... 98674.html

viewtopic.php?f=50&t=3110&p=12074&hilit=multi+meter#p12074
http://garage.grumpysperformance.com/index.php?threads/chasing-a-crazy-electrical-glitch.986/

http://www.oreillyauto.com/site/c/detai ... &ppt=C0335

http://www.nelcoproducts.com/heat-shrin ... MgodIj8AzQ

http://www.alliedelec.com/search/produc ... U=70113992

http://www.harborfreight.com/42-piece-m ... 67598.html

http://www.harborfreight.com/120-piece- ... 67530.html

http://www.harborfreight.com/127-piece- ... 67524.html

http://www.homedepot.com/s/wire+stripper?NCNI-5
http://www.homedepot.com/p/Ideal-Stripm ... 819657-_-N

http://www.alliedelec.com/search/produc ... U=70222843

http://www.sears.com/craftsman-professional-dual-heat-soldering-gun/p-00927320000P

I can,t believe the number of times I use this insulation rubber shrink tube sections ,to make electrical splice repairs so it makes a great deal of sense to buy in the larger package sizes as you get 5-7 times as much tube for less than 3 of the smaller blister packs contain

 

[grumpyvette]

Re: Relay/s, Voltage Drop/s, Current Flow, Grounds and ... m
http://garage.grumpysperformance.co...sfire-vette-won-t-run-right.10096/#post-39656

http://garage.grumpysperformance.com/index.php?threads/got-a-cross-fire-corvette.640/#post-25768

http://garage.grumpysperformance.co...ng-tpi-crossfire-or-lt1-vette.1401/#post-9259

http://garage.grumpysperformance.com/index.php?threads/c4-c5-corvette-trouble-codes.2697/#post-7017

the symptoms sound like a defective sensor or fuel pump or fuel pump relay, but read through the links it will prove useful.
as is true with many questions here theres a few related threads that may hold the answer your looking for in the links and sub links

I bought a relay, but I don't know how to hook it up. all I see are a few weird numbers and strange symbols, what do they mean?
-a standard bosch-style relay will have 4 or 5 numbered leads (30, 85, 86, 87, and sometimes 87a). why they picked those numbers, I have no clue; but I can tell what they hook up to.

http://www.homedepot.com/s/wire+stripper?NCNI-5
http://www.homedepot.com/p/Ideal-Stripm ... 819657-_-N

http://www.alliedelec.com/search/produc ... U=70222843

http://www.alliedelec.com/search/produc ... U=70222844

• Lead color code

• Black: Coil supply

• White: Coil supply

• Red: SPDT normally open

• Blue: SPDT common

• Yellow: SPDT normally closed

85 and 87a -> Ground

86 -> Power

30 -> Output

-30 = constant [positive (+)] power (usually wired directly to car battery)
-85 = coil ground (wired to the negative (-) battery terminal or any grounded metal panel in the car)
-86 = coil power (wired to the control source. could be a switch, or it could be the car's IGN or ACC circuit.)
-87 = switched [positive (+)] power output. (when the relay coil is powered, lead/pin 87 is connected to lead/pin 30)
-87a = [on 5 lead/pin relays only] this lead/pin is connected to lead/pin 30 when the coil is NOT powered.

thanks for posting that great info

THIS MAY HELP

http://www.classictruckshop.com/clubs/e ... /relay.htm

http://www.summitracing.com/parts/dak-pac-2750

http://www.summitracing.com/parts/pro-69598

http://www.ado13.com/techs/relay.htm

http://aspwholesale.com/index.php?act=v ... uctId=5159

FusionFanatic, posted this info
"There seem to be many members who don't know what a relay is, or don't know how to wire one in. this guide is here to help solve that issue...

what is a relay?
-a relay is a device that allows you to control a high-current electrical load with a low-current electrical 'signal'. they are usually electro-magnetic, but are also available in solid-state forms. they can be used with a switch (to allow control of a high-current load with a small switch) or they can be hooked up to a switched power source in the car like the ignition or accessory power circuits (to allow power to be switched on/off automatically with the ignition key).

Why do I need a relay?
-when hooking anything up to a car's factory wiring, it's important to remember that factory wires are designed to carry the load of only the factory installed components. they are not 'general use' power circuits like the power outlets in your house. for example, the ignition (IGN) circuit is designed to power the car's ignition system and nothing else. hooking up a high-current device to this circuit can create a fire hazard. by using a relay, you can use the IGN circuit to control a high-current device without directly powering it from the IGN circuit itself.

Is a relay hard to hook up?
-no... most relays require only 4 wires.

Where can I buy a relay, and how much do they cost?
-you can buy standard automotive relays at radio shack, autozone, walmart, or at almost any electronics store or automotive store. a typical SPST relay will cost about $5(US).

I bought a relay, but I don't know how to hook it up. all I see are a few weird numbers and strange symbols, what do they mean?
-a standard bosch-style relay will have 4 or 5 numbered leads (30, 85, 86, 87, and sometimes 87a). why they picked those numbers, I have no clue; but I can tell what they hook up to.

-30 = constant [positive (+)] power (usually wired directly to car battery)
-85 = coil ground (wired to the negative (-) battery terminal or any grounded metal panel in the car)
-86 = coil power (wired to the control source. could be a switch, or it could be the car's IGN or ACC circuit.)
-87 = switched [positive (+)] power output. (when the relay coil is powered, lead/pin 87 is connected to lead/pin 30)
-87a = [on 5 lead/pin relays only] this lead/pin is connected to lead/pin 30 when the coil is NOT powered.

here is the bottom view of a standard 4-lead Bosch-style automotive SPST relay

here is what happens inside the 4-lead/pin SPST relay. on the left, the coil is NOT powered. on the right, the coil IS powered. notice the switch changes positions when the coil is powered. when the coil is powered, pins 30 and 87 are connected. when the coil is NOT powered, then pin 30 is not connected to anything, therefore it is in the 'off' position.

here is the bottom view of a standard 5-lead Bosch-style automotive SPDT relay. you'll notice that the only difference is the addition of the 87a lead/pin.

here is what happens inside the 5-lead/pin SPDT relay. you'll notice that instead of an 'off' position, there is an electrical contact (87a). on the left the coil is NOT powered, and pins 30 and 87a are connected. on the right the coil IS powered, and pins 30 and 87 are connected.

here is a typical setup to control power to a carPC via the car's ACC/IGN circuits. this is generally use for laptop installs or 'no-write' setups (not good for normal carPC because abruptly cutting power without proper shutdown can cause data corruption);

I want to use the relay to turn on/off with the car. how do I hook that up?
-connect lead/pin 86 to the car's IGN, or ACC circuit. these circuits can be tapped into in the wiring harness that goes to your car's key switch. the ACC circuit can also be tapped into at the fuse box or in the stock radio harness.

What is the difference between the ignition (IGN) and the accessory (ACC) circuit?
-they are both powered when they key is in the 'RUN' position, and they are both not-powered when they key is in the 'OFF' position.


IMAGE: 1. Voltage & Current Parameters of the relay in-scripted on the Case of the relay.

2. Voltage & Current Parameters of the relay in-scripted on the Case of the relay.

Most relays are available in different operating voltages like 5V, 6V, 12V, 24V, etc. If the required operating voltage is supplied to the relay, the relay is activated. The operating voltage of a relay is generally in DC.Small signal relays and low voltage power relays are usually in DC, but mains control relays and contactors quite frequently have AC coils.The rest of the terminals of a relay are used to connect either a AC(generally 50/60Hz) or DC circuit. The switching and contact pins of the relay have their respective Maximum voltage and current ratings/Parameters. These Parameters are generally in-scripted on the plastic or PVC case of the relay.On the contact ratings, they will frequently have something like 5A@250VAC / 10A@12VDC. These are the figures you have to be within. Having said that you can run a higher current than stamped on it if your voltage is lower, they aren't directionally proportional though and the datasheet for the relay should be consulted. If a relay is overloaded, it can burn out and damage the circuit or appliances connected to it. Be sure to choose a relay that can handle your voltage and current requirements to ensure the relay coil doesn't burn out and your circuit doesn't get damaged.

Choosing a Proper Relay Amperage
How to calculate for the Correct Relay


Relay Ratings and Limits
Relays often have two ratings: AC and DC. These rating indicate how much power can be switched through the relays. This does not necessarily tell you what the limits of the relay are. For instance, a 5 Amp relay rated at 125VAC can also switch 2.5 Amps at 250VAC. Similarly, a 5 Amp relay rated at 24VDC can switch 2.5 Amps at 48VDC, or even 10 Amps at 12VDC.
Volts x Amps = Watts - Never Exceed Watts!
An easy way to determine the limit of a relay is to multiply the rated Volts times the rated Amps. This will give you the total watts a relay can switch. Every relay will have two ratings: AC and DC. You should determine the AC watts and the DC watts, and never exceed these ratings.

Example Calculations
AC Volts x AC Amps = AC Watts DC Volts x DC Amps = DC Watts
Example: A 5 Amp Relay is Rated at 250 Volts AC. 5 x 250 = 1,250 AC Watts Example: A 5 Amp Relay is Rated at 24 Volts DC.
5 x 24 = 120 DC Watts
If you are switching AC Devices, Make Sure the AC Watts of the Device you are Switching DOES NOT Exceed 1,250 when using a 5A Relay. If you are switching DC Devices, Make Sure the DC Watts of the Device you are Switching DOES NOT Exceed 120 when using a 5A Relay.
Resistive and Inductive Loads
Relays are often rated for switching resistive loads. Inductive loads can be very hard on the contacts of a relay. A resistive load is a device that stays electrically quiet when powered up, such as an incandescent light bulb. An inductive load typically has a violent startup voltage or amperage requirement, such as a motor or a transformer.
Startup and Runtime Loads
Inductive loads typically require 2-3 times the runtime voltage or amperage when power is first applied to the device. For instance, a motor rate at 5 Amps, 125 VAC will often require 10-15 amps just to get the shaft of the motor in motion. Once in motion, the the motor may consume no more than 5 amps. When driving these types of loads, choose a relay that exceeds the initial requirement of the motor. In this case, a 20-30 Amp relay should be used for best relay life.


https://relaypros.com/choosing_proper_amperage.htm

https://www.12voltplanet.co.uk/relay-guide.html

https://www.instructables.com/id/All-You-Need-to-Know-About-Relays/
-the 'ACC' circuit is powered when the key is in the 'ACC' position, but is not powered when the key is in the 'START' position. when the key is turned, power to the relay will turn on as the key passes the 'ACC' and 'RUN' positions, then turn off in the 'START' position, then turn back on as the key is released (springs back to the 'RUN' position. this is not an issue if you're using a manual on/off switch, or have a delayed on startup controller.

-the IGN circuit is powered when the key is in the 'START' position, but is not powered when the key is in the 'ACC' position. this circuit avoids the issue stated above, but requires that the key is left in the 'RU' position if you want to use the carputer with the engine off. on some cars, this can burn out the ignition coil.

I bought a 5-pin relay, can I still use it as a simple on/off switch instead of a changeover switch?
-yes. simply leave pin 87a disconnected.

My relay has more than 5-leads/pins?
if your relay has more than 5-leads/pins then is is most likely a DPDT, MPDT, or MPMP relay (M=multiple). it will work the same way, it simply has two or more separate switched inputs/outputs inside it. regardless of the number of switched contacts, it will still use a single coil, so it will still be controlled by a single power source.

Are there others types of relays other than the standard 'bosch style automotive relay'?
yes, just like regular switches, there are several different types, sizes, and styles of relays. some have multiple switched contacts, some are circuit-board mountable, some have high-current capacity, some have low-current capacity, some use higher or lower voltage coil power (generally you would only use a 12v coil in a car).

What is a 'valet switch'?
-the 'valet switch' is a standard SPST switch wired between the coil power source and pin 86. it allows you to leave the relay turned off, so nobody (including a 'valet' driver) can turn your carPC on. how effective this will be depends on how well you hide the switch (it should be accessible, but hidden from plain sight).

does a relay take the place of a fuse?
-no! a relay provides no protection from overload or short-circuits.

do I need to use a fuse if I use a relay?
yes! you must still fuse your power wires!"

14 ga is not heavy enough for a 30 amp load on most aux fans without heating up the wire, 12 ga is MARGINAL, Id go 10 ga stranded,

sensors generally get 12-14 ga anything that carries serious amps is probably 10 ga
and if its for a starter or alternator, or battery it is probably significantly heavier gauge, if your replacing a broken wire you can of course measure to find the old gauge size
http://www.engineeringtoolbox.com/amps-wire-gauge-d_730.html

http://www.sunforceproducts.com/Support Section/Solar Panel & Charge Controllers/WireGaugeSelectionTable.pdf

yes I know your likely to just use the 14 ga or 12 ga you have, but after you do feel the wire after the fans run for 15 minutes and youll see why I strongly suggest 10ga stranded wire on any aux fan application, its also a good idea to install a small indicator light, on your dash, in the fan circuit so you know when the fans running, and you can usually buy temp sensors that will turn on the fan at a preset temp .
The engine's electric fan switch is mounted into the cooling passage of the radiator or into one of the lower coolant pipes coming from the bottom of the radiator. The fan switch is a temperature sensitive two stage thermal switch that remains open (OFF) until the coolant reaches a certain temperature.

The 2-stage thermal switch essentially is 2 thermal switches that have been combined into one thermal switch. The stage 1 or low speed circuit is closed (ON) when the coolant temperature reaches approximately 203°F (95°C). The stage 2 or high speed circuit is closed (ON) when the coolant temperature reaches approximately 221°F (105°C).

The thermal switch has three terminals and is used to complete a series circuit. , the thermal is fed positive battery current and the switch, when closed (ON), completes the circuit for the positive battery voltage for the cooling fan(s).

http://www.aa1car.com/library/electric_cooling_fan.htm

http://www.the-fan-man.com/shop/185fh-3 ... l?cPath=30

http://www.summitracing.com/parts/DER-16749/

look thru this linked info, the links help[/color]

I've generally used a separate aftermarket temp sensor
(generally mounted in the intake manifold or water pump casting)
set to kick on the fans in any added fluid coolers or radiator fans etc. at about 180F

Relay/s, Voltage Drop/s, Current Flow, Grounds and ... more

A relay is nothing more than a device that uses a low-current signal to operate a high-current circuit, he solenoid on your starter is a type of relay that uses the low-current signal from your starter switch to operate the high-current circuit between the battery and the starter motor...

garage.grumpysperformance.com

Why A Relay

Hi, Im installing an electric fuel pump for a nat aspirated engine which draws 4.5 amps. I would like to know why I would want to use a relay harness setup vs wiring straight to battery with a fused link. Is it so that the ignition is involved to eliminate a dead battery? help thanks jim use...

garage.grumpysperformance.com

RPC R3108: Electric Fan Thermostat Switch 3/8 NPT - JEGS

Get the Best Performance with RPC Electric Fan Thermostat Switch 3/8 NPT R3108 parts at JEGS. Shop Now at the Guaranteed Lowest Price!

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cooling off that c4 corvette

as always, posting clear detailed pictures of any custom mods, you do to any of your cars, from several perspective angles , along with a detailed description of what you were trying to accomplish and the theory behind any mods being done would be VERY WELCOME! 85 and 87a -> Ground 86 -> Power...

garage.grumpysperformance.com

12V 30 40 SPDT Bosch Style Automotive Relays & 5 Wire Socket Harness (1/Pack) | eBay

12 Volt 40/30 amp 5-prong relays. Relays and sockets are used for many car electronic applications to turn on/off almost any device.

www.ebay.com

12V 30 40 SPDT Bosch Style Automotive Relays & 5 Wire Socket Harness (1/Pack) | eBay

12 Volt 40/30 amp 5-prong relays. Relays and sockets are used for many car electronic applications to turn on/off almost any device.

www.ebay.com

Temu | Explore the Latest Clothing, Beauty, Home, Jewelry & More

was discontinued - Temu

www.temu.com

http://www.harborfreight.com/3-1-2-half ... 95670.html

http://garage.grumpysperformance.co...orvette-with-flicker-on-dash-and-radio.13593/

http://garage.grumpysperformance.co...rical-glitches-in-newer-cars.5492/#post-18411

http://garage.grumpysperformance.com/index.php?threads/digital-dash-swap-questions.3399/#post-8970

http://garage.grumpysperformance.co...er-repair-or-replacement-link.1006/#post-8030

http://garage.grumpysperformance.com/index.php?threads/c4-c5-corvette-trouble-codes.2697/#post-6985

http://garage.grumpysperformance.co...ntermitant-electrical-glitches.987/#post-1739

 

[Indycars]

A lot of older vehicles and their components suffer from Voltage drop, voltage drop occurs when the circuit can't transmit the source voltage to the load, if we follow Ohm's law we disover that if a circuit has constant resistance value and we reduce the Input voltage that the current increases proportionally,

I'm glad you are adding to the content already, sure didn't take you long. Wish I had the writing gene!!!

1.) Maybe I'm not reading this correctly, so please bear with me..... if I = E / R, and the voltage (E) drops, then I (Current) would also drop. :?:

 

[SS402]

Voltage is inversely proportional to Current and vice versa if the Resistance value doesn't change.

 

[Indycars]

Re: Relay/s, Voltage Drop/s, Current Flow, Grounds and ... m

We all know that to carry a certain current we need to have a specific
size wire, the higher the current the bigger the wire. Well there is
more to story........the longer the wire, the bigger it needs to be to
carry the same current.

Below is a table that helps with getting the right size wire when considering
both current and distance.

http://www.offroaders.com/tech/12-volt- ... e-amps.htm

 

[grumpyvette]

Re: Relay/s, Voltage Drop/s, Current Flow, Grounds and ... m

wow nice chart! that will come in handy for cars especially for things like wiring cooling fans and head lights

http://garage.grumpysperformance.com/index.php?threads/digital-dash-swap-questions.3399/#post-8970
http://www.how-to-build-hotrods.com/fuse-panel.html
http://www.delcity.net/store/Sealed-Mini-Fuse-Panels/p_803796
http://www.rbracing-rsr.com/wiring_ecu.html
http://www.hotrod.com/how-to/engine/1408-how-to-wire-your-own-race-car/
http://www.onallcylinders.com/2013/12/05/wiring-101-basic-tips-tricks-tools-wiring-vehicle/
http://www.themotorbookstore.com/automotive-electrical.html

http://www.amazon.com/Automotive-Wi...automotive+electrical+books#reader_1932494871

Solder Wire for Electrical Soldering

FEATURES Lead-free solder wire: lead-free solder wire with rosin core; It weighs 100 g/ 0.22 lb; The size of solder wire roll is 5.4 x 5.4 x 2.8 cm/ 2.1 x 2.1 x 1.1 inches. Relative parameters: the diameter of the electrical soldering wire is 0.8 mm/1.0mm (0.031/0.039 inch); Sn/ Cu: 99.3%/ 0.3%...

www.peonlyshop.com

Typical Current Loads for Automotive Systems, Lighting and Accessories:
Engine Idling (no lights or accessories on) - 35 to 50 amps. This will vary depending on the number of cylinders (more cylinders draw more power for the fuel injectors and coils), the type of fuel injectors (some draw higher amp loads than others), the type of ignition system (single coil or multi-coil), the amp draw of the PCM, and the fuel pump (the amp draw will be higher with higher pressure systems).

Engine Off (nothing on) - 40 to 50 milliamps (power drain by modules in sleep mode, antitheft system and keyless entry)

Ignition Coil (single oil-filled coil older vehicle) - 3 to 4 amps.

Ignition Coil (single DIS coil newer vehicle) - 5 to 6 amps.

Ignition Coil (coil-on-plug) - 6 amps per coil.

Ignition System (primary circuit) - 6 to 20 amps.

Fuel Injectors - 4 to 6 amps peak, 1 amp hold

Electric Fuel Pump (depends on pressure and flow) - 4 to 12 amps

Electric Cooling Fan (depends on size) - 6 to 30 amps

Headlights (halogen low beam) - 8 to 9 amps per pair

Headlights (halogen high beam) - 9 to 10 amps per pair

Headlights (halogen high and low beams combined) - 17 to 19 amps

Headlights (High Energy Discharge) - 12 to 14 amps during initial start, 7 to 8 amps once bulbs are hot

Headlights (LED) - 0.6 to 1 amps per bulb

Small bulbs (incandescent) - 0.3 to 0.4 amps per bulb

Small bulbs (LED) - 0.04 to 0.06 amps per bulb

Starter Motor - 200 to 350 amps

500 Watt Sound System - 42 amps

Electric Rear Window Defroster - 10 to 20 amps

Windshield wipers - 2 to 10 amps depending on load

Heated Seats - 3 to 4 amps per seat

Power Windows - 3 amps

Electric Power Steering - 2 to 40 amps depending on load

Air Conditioner Compressor Clutch - 2.5 to 5 amps

Heater A/C blower motor (depends on load, size and speed setting) - 2 to 30 amps



any chance you have access to something similar to refer to in 120 volt current /25 foot increments?
common outlets
any chance you have access to something similar to refer to in 220 volt current /25 foot increments?
heavy equipment like drill press, compressors,lifts, mills etc.
for wiring up a shop?

I found these, not as nice but may help

Item# 1677827

having a quick easy to use auto voltage test checker helps speed the diagnosis

as most of us who work on cars know chasing minor electrical glitches is a P.I.T.A. and it helps a good deal to have at least a minimal quality multi meter and test leads, and a scan tool, that can be used to, locate isolate and test THRU insulation on wires, and a tool to pull trouble codes and do minimal programming.

http://www.amazon.com/AutoXray-6000-EZ- ... cr_pr_pb_t

http://www.fluke.com/Fluke/usen/Digital ... ?PID=55990

http://www.harborfreight.com/5-in-1-dig ... 98674.html

http://www.harborfreight.com/ac-dc-digi ... 37772.html

THATS WHY YOU BUY THE CONNECTORS TOOLS WIRE AND LEARN TO WIRE THE CAR YOURSELF!
anytime you price out a car custom wire harness youll be in shock at the absolute absurd prices quoted.
personally Id hit the local salvage yards Id bet you could negotiate the price of a complete wire harness from a fairly new truck for under $200
when I got quotes on wiring my shop .. read this link
http://garage.grumpysperformance.com/index.php?threads/how-to-wire-a-shop.5/

http://www.rowand.net/Shop/Tech/AutomotiveElectricalConnectors.htm
now Ive wired more than a few cars
http://garage.grumpysperformance.com/index.php?threads/sources-for-auto-elecrtrical-connectors.3105/

https://www.cableorganizer.com/shrinkflex-shielded-2-1/

http://garage.grumpysperformance.co...-engine-harness-integration.11148/#post-49939

http://www.repairconnector.com/

http://www.delcity.net/store/Wire-C...es/r_IS1028?&gclid=CJzJz8nJzckCFQaJaQodyVQJHA

http://www.wiringproducts.com/general-motors-connectors-sockets

if you work around older cars for awhile your sure to notice a great many problems can be traced back to faulty, corroded or broken electrical connections, sockets and connectors or fuses ans wiring that need to be repaired or replaced, especially in moist areas, and in many cases youll be far ahead to just buy a new connector and carefully solder it in and use shrink tubing over the splice

having a wire roll caddy , thats easy to access or fabricating one for working around the cars helpful
I can easily see where some simple fabrication skills, some careful measuring and a bit of rough design work on a pad with a ruler and pencil and a quick trip to harbor freight and home depot, to buy a few components , a power drill, a few bits screws and some 1/2" conduit ,a couple 2 foot long sections of 2" angle aluminum,could rather easily result in a rather well designed electrical wire spool holder rack of several types depending on your shops needs

http://www.globalindustrial.com/g/stora ... pool-racks

http://www.globalindustrial.com/p/stora ... ddy-RT4-8S

automotive electrical connectors and related info

THIS IS A GOOD VALUE

https://www.northerntool.com/shop/tools/product_200356620_200356620?cm_mmc=Google-pla&utm_source=Google_PLA&utm_medium=Electrical > Terminal Kits + Organizers&utm_campaign=Northern Industrial Tools&utm_content=163443&gclid=EAIaIQobChMIq4Gj3qeW2AIVVrXACh3l2QRxEAYYCCABEgK4afD_BwE



http://repairconnector.com/

http://www.homedepot.com/s/wire+stripper?NCNI-5
http://www.homedepot.com/p/Ideal-Stripm ... 819657-_-N

http://www.alliedelec.com/search/produc ... U=70222843

http://www.sears.com/craftsman-professional-dual-heat-soldering-gun/p-00927320000P

 

[mathd]

Re: Relay/s, Voltage Drop/s, Current Flow, Grounds and ... m

nice write-up, am changing my headlight circuit to relay feed this season too .

Voltage is inversely proportional to Current and vice versa if the Resistance value doesn't change.

One thing i don't agree if, if your headlight have a fixed resistance and are feed a lower voltage (10v) they will draw less current.
following owm's law.
if the headlight is lets say 50 watt x 2 = 100 watt (random numbers)
now if you have 100 watt / 12 volt(headlight rating) = 8.33 amp the headlight circuit draw.
now lets try this
volt / amp = resistance
12 / 8.33 = 1.44 Ohm fixed load for both headlight.
Volt / resistance = amp draw
now lets say we have 10 volt at the lamp.
10 / 1.44 = 6.94 Amps for both headlight.

So the device will draw less current when feed a lower voltage.
The voltage is lower at the end of the wire because the current draw from the headlight is too hight for the fixed wire's resistance but the current draw dont go up because of the voltage drop since the headlight get feed a lower voltage into its fixed resistance .
Both wire resistance and the device(hadlight) fixed resistance add together and also act as a voltage divider

Still i agree that a relay is much more efficient, safe, and the device get feed its proper voltage.

I agree on everything else on your post.

 

[mathd]

Re: Relay/s, Voltage Drop/s, Current Flow, Grounds and ... m

wow nice chart! that will come in handy for cars especially for things like wiring cooling fans and head lights


any chance you have access to something similar to refer to in 120 volt current /25 foot increments?
common outlets
any chance you have access to something similar to refer to in 220 volt current /25 foot increments?
heavy equipment like drill press, compressors,lifts, mills etc.
for wiring up a shop?

I found these, not as nice but may help

Lets say you have a 20 ft 10 gauge wire at 0.999 resistance per 1000 ft according to your chart
0.999 / 1000 * 20 = 0.01998 Ohm
So you dont want too much voltage drop(i dont know how much because am not doing this often with household wiring)
but usually if you have a 20 amp load following ohm laws it should looks like this:
20 amp * 0.01998 ohm = 0.3996 volt dropped (now is 0.3996 of voltage drop acceptable for a 125 or 220 line?, i have no clue :/)

But its best to check some AWG rating chart for maximum current load vs wire size.

 

[Indycars]

Re: Relay/s, Voltage Drop/s, Current Flow, Grounds and ... m

any chance you have access to something similar to refer to in 120 volt current /25 foot increments?
common outlets
any chance you have access to something similar to refer to in 220 volt current /25 foot increments?
heavy equipment like drill press, compressors,lifts, mills etc.
for wiring up a shop?

No I don't have any tables for 120 or 220 volt, but I will keep my eyes open.

 

[grumpyvette]

Re: Relay/s, Voltage Drop/s, Current Flow, Grounds and ... m

if you work around older cars for awhile your sure to notice a great many problems can be traced back to faulty, corroded or broken electrical connections, sockets and connectors or fuses and wiring that need to be repaired or replaced, especially in moist areas, and in many cases youll be far ahead to just buy a new connector and carefully solder it in and use shrink tubing over the splice

having a wire roll caddy , thats easy to access or fabricating one for working around the cars helpful
I can easily see where some simple fabrication skills, some careful measuring and a bit of rough design work on a pad with a ruler and pencil and a quick trip to harbor freight and home depot, to buy a few components , a power drill, a few bits screws and some 1/2" conduit ,a couple 2 foot long sections of 2" angle aluminum,could rather easily result in a rather well designed electrical wire spool holder rack of several types depending on your shops needs
https://www.jegs.com/i/JEGS/555/10308/10002/-1

ford remote starter relays can be used in many higher amp fan circuits

http://www.deutschconnector.com/

http://www.leashelectronics.com/
M22759/16 Tefzel Wire
Insulation: Ethylene-Tetrafluoroethylene (ETFE)
Tin Plated Copper Conductor
Voltage Rating:
600 Volts
Temperature: 150°C


Standard wall ethylene-tetrafluoroehtylene (ETFE) insulation ( also known as Tefzel ) designed for aerospace applications where weight, dimensional tolerance, and mechanical durability are required. This wire exhibits high chemical and radiation resistance. The tin plated copper conductor offers a cost savings over the silver plated high strength copper alloy which is available on M22759/17.

http://www.globalindustrial.com/g/stora ... pool-racks

http://www.globalindustrial.com/p/stora ... ddy-RT4-8S

automotive electrical connectors and related info

http://repairconnector.com/

viewtopic.php?f=70&t=1443&p=28051&hilit=shrink#p28051

http://www.connectorsupply.com/catalog/ ... 6ae598085b

http://www.bing.com/images/search?q=Wir ... tedIndex=0

http://www.rjminjectiontech.com/collect ... connectors

http://paceperformance.com/c-142454-ele ... tails.html

viewtopic.php?f=50&t=3110&p=8302&hilit=electrical+connectors#p8302

viewtopic.php?f=36&t=3439&p=19529&hilit=owner+wiring#p19529

http://www.rockauto.com/catalog/x,carco ... BConnector


http://www.ecklers.com/search.asp?actio ... chHistory=

http://www.eficonnection.com/eficonnect ... eType.aspx

http://www.suresealconnections.com/

http://www.repairconnector.com/

http://www.waytekwire.com/automotive-connectors.htm

http://www.rowand.net/Shop/Tech/Automot ... ectors.htm

http://www.vette2vette.com/

http://www.mamotorworks.com/corvette-3-408-1079.html

 

[grumpyvette]

Re: Relay/s, Voltage Drop/s, Current Flow, Grounds and ... m
http://www.wiringproducts.com/copper-battery-terminals

http://garage.grumpysperformance.co...-auto-elecrtrical-connectors.3105/#post-68805

http://www.jegs.com/c/Batteries-Accessories_Battery-Cable-Kits-and-Terminals/165203/10002/-1?N=1165203&Ns=P_SalesVolume|1&Nrpp=&Tab=SKU&storeId=10001&catalogId=10002&langId=-1&No=30

if you can locate a wiring diagram and validate the correct connector type(s) used a custom wire harness can usually be hand made for most applications at a considerable cost savings
it has become rather obvious to me, after watching my neighbor try to repair his older muscle cars under dash wiring, that many guys have no concept of how to correctly make a wire splice repair so i figure I WILL post the basics here. yeah watching guys who think twisting a bit of wire together and covering it with electrical tape or using a couple wire nuts is the correct way to splice wire is about to make me a bit more insane than I already am.
TOOLS YOULL NEED
BE AWARE THE WIRE GAUGE AND RELAY AMP RATES VARY SO SHOP CAREFULLY
http://www.aliexpress.com/item/10pcs-Ca ... 80067.html
http://www.harborfreight.com/127-piece- ... 67524.html

https://www.cableorganizer.com/shrinkflex-shielded-2-1/

HAVING A HIGH AMP (160-220 amp) QUALITY ALTERNATOR AND A DECENT BATTERY, WITH GOOD CLEAN CABLE CONNECTIONS HELPS IMMENSELY
and I would suspect that,just a thought?
would not adding a relay and the more complex wiring to feed the device and adding the relay,make the electrical circuit,
far out cost the simple use of a marginally heavier gauge wire, and switch, that would eliminate the need for the relays use? in some applications?


http://custombatterycables.com/product_info.htm

http://www.summitracing.com/parts/tff-8173nep/applications/year/1996

http://www.cabletiesandmore.com/america ... -p-636.php
http://www.cabletiesandmore.com/america ... -p-638.php

http://www.cableorganizer.com/wire-loom ... eloom.html
a DECENT QUALITY WIRE STRIPPER

http://www.bing.com/shopping/weller-wel ... ORM=CMSPEE
I figured Id point out a few basics
that I find it hard to believe are commonly over-looked
and
that's the fact that you'll want to
check the condition of the batteries and electrical connections in any meter you use.
before you go doing any testing.
I can remember several times that I've found
9 volt and AA batteries inside multi meters that were corroded and leaking acid,
and remember guys telling me injectors were defective, only to find later that the meter they used to test with was defective or the internal fuses or battery was dead, or 90% dead and internal connections in the multi meter were corroded.
and as a result, connections internally were damaged so badly that the connections were turned to white metallic salts.
Ive also watched and seen guys try to check for good grounds , or ohms resistance or voltage and spend a lot of wasted time ,
because the multi-meter had a blown internal fuse , or the connector probes & leads, that did not fit,
and were not designed to be used with that particular multi-meter.



having a wide assortment of different multi meter test leads available is a huge benefit while testing
the clip test leads that test thru a wires insulation without much damage are a big help

most internal fuses will have the voltage/amps stamped on them,
any mechanic should have an assortment in his tool box, as your constantly going to need replacements while testing auto related issues

always make a point of flipping the multi meter too low range OHMS and touching the leads from common (BLACK) to (RED) test lead tips,
to watch the display or needle bounce to verify the multi meters functioning,
then place the black ground or common lead on a cars grounded chassis,
and touch the red probe to a fuse and verify it reads 12-14 volts current


https://media.distributordatasoluti.../4133557fb8456fa5ec26aff60729042350758d52.pdf

anything under about 200 watts rating is basically a P.I.T.A. to use and a TOY in my opinion simply because you cant quickly bring the wire and solder up to the correct temps

BASIC SOLDER GUN
http://www.sears.com/craftsman-professional-dual-heat-soldering-gun/p-00927320000P
BETTER SOLDER GUN

good 60/40 lead/tin solder
http://www.bing.com/shopping/4-oz-40-60 ... ux&FORM=EG

http://www.radioshack.com/product/index ... d=12582872

READ THRU THIS LINK
http://www.aaroncake.net/electronics/solder.htm

the process is rather easy and simple top do with practice, assuming the standard 14ga-12 ga under dash wiring ,you simple strip off about 1.25" of insulation on each end of the two wires, larger ga wire will require a longer section, of insulation be removed, once thats done you spin the stranded wire end between your fingers

to twist it tightly so it won,t leave exposed copper wire ends and then slide on a 2.5" to 3" long section of heat shrink tube , (don,t forget to do this) now dip both the twisted copper wire ends in the flux, then twist them both together tightly in a spiral so they won,t easily separate, now add a dab of flux because much of its most likely been removed during the twist process but if you don,t do it before you twist its not going to get full coverage on the strands.
ok ideally you,ll have decent access and have the shrink tube slid on the lower wire so it won,t slide down while you solder, use the tip of the heated solder gun on the far side of the two twisted wires and touch the solder to the near side as it heats allowing the fluxed surface to draw the solder once its liquid over and around the spliced copper wire surface, once its well coated pull the solder and solder gun away , it the surface is well coated and smooth silver in appearance you can let it cool a bit then slide on the heat shrink tube , center it over the spice and use the heat from the tip of the solder gun placed near too ,but never touching, and while smoothly moving the guns tip so as not to over heat or burn the shrink tube until it firmly shrinks and hugs the spliced and soldered copper wire, making the soldered splice at least semi protected, the shrink tube, acts as insulation and a corrosion protective barrier , BTW a bit of BEES WAX can be heated and melted over the ends of the shrink tube where it joins the original insulation and used as a increased effective,moisture barrier.

you can,t always trust scanners suggestions either, I recently had a code scanner suggest a cooling fan relay was defective,
replacing it with a known good relay that was working in an identical car had no effect neither relay tested bad either..
the problem was tracked down to a loose ground and a heat sensor that tested good at its rated ohms resistance, but failed to trigger the relay
experience suggested I test the relay by inserting a resistor of the known rated ohms to trigger the relay into the pigtail that connected to the sensor,
a simple test like that proved the sensor was defective as the fan and relay function with the resistor in the pigtail.

https://www.sparkfun.com/products/10969

https://www.jameco.com/z/GB115-1-8-1-4-and-1-2-Watt-Resistor-Grab-Bag-Tolerances-2-5-10-_134130.html

https://www.diyaudioandvideo.com/Electronics/ResistorColorCodes/


related info

http://www.agcoauto.com/content/news/p2_articleid/157

http://www.fluke.com/fluke/uses/com...articlecategories/electrical/diagnosevoltdrop

http://www.aa1car.com/library/tselec.htm

http://www.hotrod.com/how-to/interior-electrical/116-0507-top-10-electrical-fixes/

http://custombatterycables.com/product_info.htm


now one of the lesser known causes of u-joint failure , is the result of missing or high electrical resistance engine electrical grounds,
you should always ground the engine and transmission to the chassis ground in at least two places.
its not all that uncommon for a badly grounded engine to need the u-joints , radiators , pilot bearings and starters replaced on a much higher frequency,
simply because electricity will take the path of least resistance, to flow and if the engines rubber transmission and motor mounts,
and rubber exhaust system hangers make the drive shaft a partial path for the engines electrical ground, that current can and will eventually cause damage to the u-joints.


"from ARCOAUTO
If the cables, grounds and terminals work as designed, current flow is not a problem. When cranking the vehicle, we turn the key and electricity flows from the battery to the starter motor, through a solenoid. We need the solenoid, because the key switch cannot conduct the high amperage needed to operate the starter. The solenoid acts like a heavy-duty relay. It allows the light-duty key switch to control the high-amperage starter motor.

After flowing through the starter, the current returns to the battery through the engine block. They connect the engine to the electrical system with a heavy cable, attached to the negative battery terminal. This completes the circuit. The starter uses 275 amps to turn and the same current returns to the battery. Current flow on both cables equals 275 amps. The current returning to the battery equals that leaving it.
Problems occur when corrosion and loose connections cause high resistance. The ground cable may only be able to flow 250 amps. If the starter pulls 275 amps, twenty-five amps will find another path to the negative terminal. This is known as transient current flow; electricity taking a path, other than that designed, to return to the battery. The end result can be considerable damage to seemingly unrelated components.
Transmission and suspension components are not designed to flow electricity. As the current flows through them, metal can be transferred from on part to another. This is similar to the electroplating process. In time the parts are destroyed and there may be a major failure.

Keeping all battery terminals clean, tight and with proper connections can help prevent transient current flow.


ost folks have never heard of a transient current flow. Transient current flow can cause thousands in damage to a vehicles. Normally there are very few outward signs until it is too late. Fortunately it can also be detected and prevented, with a few simple steps.

When there is an electrical load in our vehicle, current flows from the battery to the load. A positive current leaves the battery and travels through wires to the accessory. The same amount of current must also return to negative side through a ground. The ground may be provided by a wire or sometimes the vehicle body. The body is electrically attached to the negative terminal.

The current flow leaving and returning to the battery has to be equal

CORRECT GROUNDS

LOOSE CORROADED GROUNDS

Battery terminal corrosion is a symptom of another problem
A few symptoms of transient current flow

• 
  
  
  • 
    
    
    • Premature transmission failure
    • Early or repeat tie rod failure
    • Early or repeat wheel bearing failure
    • Early or repeat rack and pinion failure
    • Flickering or pulsing headlamps
    • Erratic dash volt meter
    • Unexplained or repeat electrical failures "

btw youll eventually be tempted to use crimp connectors or wrap wire around a screw connector on a sensor or electrical component

do your self a big favor and use ring end connectors

but here again SOLDER THE CONNECTOR TO THE WIRE LIKE THIS, AND SLIDE ON SHRINK TUBE INSULATION LEAVING ONLY THE RING END EXPOSED ITS FAR LES LIKELY TO CAUSE PROBLEMS

10 ga wire should be all thats required

theres are 60 and 80 amp 12-14 volt relays with pig tails, or places to connect ring terminal connectors available, its common for high capacity fans to draw 35-40 amps at times, so using a 60-80 amp relay and the required minimum fuse amp rated circuit sure won,t hurt

Item# 1677827

having a quick easy to use auto voltage test checker helps speed the diagnosis

as most of us who work on cars know chasing minor electrical glitches is a P.I.T.A. and it helps a good deal to have at least a minimal quality multi meter and test leads, and a scan tool, that can be used to, locate isolate and test THRU insulation on wires, and a tool to pull trouble codes and do minimal programming.

http://www.amazon.com/AutoXray-6000-EZ- ... cr_pr_pb_t

http://www.fluke.com/Fluke/usen/Digital ... ?PID=55990

http://www.harborfreight.com/5-in-1-dig ... 98674.html

http://www.harborfreight.com/ac-dc-digi ... 37772.html

use of and taking the time and effort, when building or repairing the wiring on any custom car, to install a $5 -$7, UNIQUE for each electrical component , quick connect indexed water resistant screw-up proof, male/female connector combo, that allow's you too quickly connector remove a distributor or other component from the cars wire harness and re-install it with little chance of screwing up the electrical connections is almost always a good idea

obviously measuring the current draw would help here
http://www.ecutool.com/DT-337-Mini-ACDC ... _7294.html

viewtopic.php?f=70&t=3504&p=33365&hilit=solder+ring#p33365

http://www.ebay.com/itm/Heavy-Duty-Auto ... 0375347709

http://www.wiringproducts.com/contents/ ... relay.html

http://www.jegs.com/i/Derale/259/16738/10002/-1

http://www.cableorganizer.com/wire-loom ... eloom.html

http://www.technooutlet.com/viac025.htm ... 1b2166c62d

a great many electrically conductive surfaces are subject to oxidation and corrosion especially things like battery grounds on frames and the newer screw on the side battery cable connections, and battery to starter connections,so coating those higher amp rated connection points with a good anti corrosive, and moisture resistant and electrically conductive paste , grease or anti-seize would seem to be a good idea.
I know I can,t be the only guy that used to occasionally find when I hit the ignition key and got a click but the starter would not work, and found that a loose battery connection on the cable was at fault!

http://www.2spi.com/catalog/vac/silver-filled-grease-techdata.html

http://www.cool-amp.com/conducto_lube.html?gclid=CNKs1MD-sMYCFZKBaQodGswC6A

http://www.w8ji.com/dielectric_grease_vs_conductive_grease.htm

http://www.carid.com/loctite/copper...Put_9z-sMYCFQGGaQodOMID_Q#product-details-tab

removing battery cable corrosion with coke, baking soda and correctly

use of a battery post cleaning brush tool is usually helpful

use of this common anti-seize paste on the connecting surfaces noticeably reduces corrosion and helps electrical conductivity

http://www.harborfreight.com/battery-terminal-cleaner-94450.html

sak-myshopage

m.smartsaker.com

sak-myshopage

m.smartsaker.com

 

[grumpyvette]

Re: Relay/s, Voltage Drop/s, Current Flow, Grounds and ... m

VOLTAGE REGULATOR, ALTERNATOR and BATTERY OPERATION

HOW IT WORKS… by Mark Hamilton

The simple explanation is provided first, as not to leave out readers who only want a sort of overall view of how a system works, without getting too technical.

Sometimes when explaining technical concepts, it’s good to use parallel comparison with a more visible and simpler working model. That is why instructors and tutorial books often use water-plumbing systems in attempt to explain various electrical occurrences. (We cannot really see volts, and amps, and ohms in wires. We use meters and other equipment to check for presence and levels of electricity, and to check up on system performance.)

In this author’s many years of experience while attempting to explain functions of the alternator, voltage regulator, battery, and electrical system power consumption; the air compressor system has been the best parallel example by far! That may be true because most people with at least limited experience with cars will have worked around an air compressor. Quite possibly fewer people who work with cars will have knowledge of hydraulic pressure differentials and pressure loss with plumbing systems. Once again, the air compressor system will be used with attempt to explain this part of our auto electrical system.

VOLTAGE (VOLT) is a measure of electrical pressure. In the compressed air system, “PSI” (Pounds per Square Inch) is the measure of pressure.

AMPERAGE (AMP, or AMPERE) is a measure of electrical current flow. In the compressed air system cubic feet of air is the similar measure of quantity.

OHM is the measure of resistance to electrical current flow–a resistance holds back the flow of electrical current. In the compressed air system, restriction, blockage, reduced passage (metered orifice) are the terms most often used to describe the same effect that resistance will have in an electrical system.

THE COMPARISON (explanation of system functions)

The battery is an electrical storage reservoir, similar in function to the air tank for the compressed air system. (Actually, the battery does not store electricity, it would be more correct to say; “the battery stores ingredients that can produce electricity.”) Both the battery and the air tank can store a source of energy in reserve, keeping energy available for the times we need it.

The alternator produces electrical power, which can operate devices that perform work for us. And the compressor produces the compressed air, which can be used as a source of power to operate tools or machinery.

The voltage regulator limits the maximum voltage in the electrical system. In the compressed air system the pressure regulator limits the maximum pressure. The voltage regulator will also cause the alternator to produce more output, when voltage (pressure) at the electrical system is low. And in the compressed air system, the pressure switch will turn on the compressor when system pressure gets low.

Lights, ignition, and accessories use power from the electrical system. Every time we switch an accessory ON, more power is drawn from the system. Voltage (electrical pressure) drops as power is drawn from the system, and then the voltage regulator causes the alternator to make more current. And in the compressed air system an impact wrench, blowgun, paint gun, or the fitting for filling a tire, can all use power (compressed air) from the system. When we use compressed air from the system, PSI (air pressure) drops, and the regulator turns the compressor ON. In the electrical system, the voltage regulator “turns the alternator ON,” or “turns OFF the alternator” as needed to maintain voltage at the proper level. And in the air compressor system the pressure regulator stops and starts the compressor as needed to maintain the proper level of pressure.

The useful electrical system will require an alternator that can produce an average of more output than we use, and the regulator will limit system voltage to the safe level we need. Like most machinery, the alternator cannot stand to work at maximum output for extended periods of time. Short bursts at maximum output are okay, but normal operation will require alternator operation at only a part of full output potential, most of the time. Alternators make heat as a by-product of making electrical power, and the more power they supply the more heat they make. Some models of alternators can stand to put out a much higher percentage of their gross output rating than others, during extended periods of operation.

Air compressors have “duty cycle” ratings. The compressor also produces heat as a by-product, and if it was called upon to run continuously while maintaining high pressure, the compressor will burn out. Some models of air compressors will have a greater duty cycle than others. Expect that a hobby shop model will not be intended to run for the long time periods that a professional workshop compressor is built for.

When the electrical system needs more power than the alternator can produce, for a short time, then the battery is already connected to the system and the battery will contribute the needed power. Entering into this picture is that the alternator must spin at sufficient RPM to produce power. And there is an alternator power output/RPM curve, where available output increases with RPM. There is also a minimum and maximum for practical alternator RPM operating range. Alternator RPM is somewhat adjustable by changing the ratio of the drive pulley at the crankshaft and alternator pulley diameters. But since the engine will run slowly at times, and rev very high at other times, there is no “perfect” pulley drive ratio for all applications. The pulley drive ratio is a compromise; and what’s acceptable at maximum RPM is the deciding point. (An alternator can be damaged with excessive RPM.) A pulley ratio that is good with 6,500 to 8,000 engine RPM on a circle track is far from ideal with the in-line six engine in “Grandma’s grocery getter.”

At low RPM, expect that early models of alternators often produced much less available output than more modern designs. And with many models of old alternators, electrical output at engine idle speed was not sufficient to support electrical demands. But when sitting at a stoplight, the battery could assist the alternator with support of the electrical system. And then when the light turned green we drove away with the engine spinning the alternator fast once again. The alternator soon replaced power used from the battery while sitting at the stop light, no harm done. System voltage will be low, when the alternator is not keeping up. (Voltage will be above 14 when the alternator is working, and about twelve and falling when supported by the battery.)

Drivers of old cars were accustomed to the lights dimming at idle, or the turn signals blinking slower–it was simply the result of low voltage when the alternator did not keep up. The older cars could get by with less than perfect performance. And with fewer electrical items to support, then the voltage did not drop off so quickly. The old cars also did not have electronics that would cease to operate at low voltage. With the duration of city traffic jams in modern times, the many accessories on a modern car, and electronics that are sensitive to low voltage, of course alternator output at engine idle speed had to get better. The newer designs of alternators can produce a lot more current at low RPM, even when the gross output rating is nearly the same with the old model.

In parallel to the electrical system, with the air compressor at marginal capacity, there will be times when system pressure gets low. As when friends come over to help with a project on the weekend, all armed with air tools to operate from the small compressor in the garage. (And as with electrical systems, this didn’t likely happen back in the 1960’s!) The small compressor cannot support an air ratchet, an impact wrench, a blowgun, and a grinder with a cut-off wheel all at once. During those times the reservoir (tank) would have to supply power (compressed air). When average use is more than the amount produced by the compressor, then system pressure falls low.

The electrical system behaves about the same. If the average output from the alternator does not keep up with electrical system power use, then the battery falls to discharged condition, and system voltage falls below acceptable level.

The table below shows about what to expect with differences in alternators that are only one generation apart. (‘60s type externally regulated compared to ‘70s type internally regulated. About the same test results have been observed on many occasions, when doing alternator up-grades. The same “stock” pulley drive ratio was with both types of alternators. (1969–1972, small block 350 engine, stock pulleys)

ALTERNATOR

COMPARRISON


Available output

at 680 RPM

Engine idle


Engine RPM required

for maximum

Available output

Externally regulated

61amp, model 10DN,

Delco alternator




8 to 10amps






2400 to 2500 RPM

Internally regulated

63amp, model 10SI

Delco alternator




35 to 40amps




1275 to 1325 RPM



One more aspect of the comparison between the electrical system and the compressed air system, and that is “PRESSURE DROP” with long “lines” used for delivery. In the electrical system long lengths of wire will have resistance, amounting to a restriction of electrical power flow. And the farther down the wire we check voltage, the lower the voltage (electrical pressure) will be. Also, with increased current flow, the voltage drop (pressure drop) will increase. In example, if we attempt to operate a really powerful electrical device such as a starter, through a long, small diameter wire, then starter performance will be poor. The starter motor will attempt to draw a large amount of current through the long, small gauge wire, and voltage will be weak at the starter end of the wire. In another example, if wires from a headlight switch all the way out to the front of the car are thin in gauge size diameter, then voltage to the lights will be low resulting with dim lights.

The same can happen with compressed air systems. In younger years, there were occasions where working with air tools at low pressure was a constant irritation. Imagine an old building, with a large compressor at the far end of a long building. Back in the 1940’s compressed air was mainly used to air-up tires, but not to provide service for busy mechanics wielding air ratchets and impact wrenches. The building was equipped with very old, small diameter steel tubing for the compressed air service. In that facility, the mechanic farthest away from the compressor did not receive air at full pressure. If an air ratchet or tool requiring a large volume of air was used, then the tool was down on power. Larger diameter tubing would have really improved performance of the air tools. Especially so when other mechanics closer to the compressor were using air before it gets to the end of the line.

The situation with the long, small diameter tubing, for compressed air, had the same effect as with a long small wire used to operate many powerful accessories. The accessory farthest down the wire will receive power at low voltage (pressure) level. Larger wire diameter will improve performance by delivering power at higher voltage (pressure.) Or… Use a system design providing a shorter length wire, which also will improve performance.

And now for those who enjoy the technical aspects of how things work, here is a more detailed explanation of system operation with the

ALTERNATOR, VOLTAGE REGULATOR and BATTERY.

The alternator will generate power to operate the electrical system plus keep the battery charged. The purpose of the voltage regulator is to regulate the amount of power output from the alternator. (Of course! What else do regulators do? Ha!) The voltage regulator will allow the alternator to make enough power to maintain proper voltage level, but not allow system voltage to rise to a harmful level.

With regulators for the alternator system, voltage limiting is the means of controlling output. (The older “generator” systems had a voltage limiter and also a current limiter, plus a “cut-out relay” that disconnected the system when the engine stopped.) If the alternator was allowed to constantly produce all the power it could, system voltage would rise to a damaging level, the battery would overcharge, components would be damaged, and the alternator would soon overheat and burn out.

With a 100amp alternator installed, we do not drive around with the alternator constantly producing 100amps. When driving a simple car, in example a ’66 Chevelle, with no accessories switched on, stock ignition, and the battery topped off with a charge, the alternator produces only about 3amps to 5amps of current! (No matter how powerful the alternator, output is limited according to system demands.)

And, in case you are wondering, the amount of horsepower used to spin the alternator changes with output. When the alternators produce only a small amount of current, the horsepower drag is very small (less than 1/3 amp). Large amount of output causes more horsepower drag (about 3 or 4 horsepower to produce 120amps output).

REGULATOR ACTIONS

Popular textbooks tell us the ideal voltage regulator setting is 14.2 volts. A range of about 14.0 to 14.6 volts is generally acceptable, and various shop manuals will typically publish about that range.

When system voltage is below the setting of the voltage regulator, then the regulator causes the alternator to produce power until voltage reaches the maximum setting of the regulator. When we first crank up the engine, battery voltage will be at about 12.5 or 12.6 volts. The regulator recognizes low voltage, and causes the alternator to produce power. Also when driving, every time we switch an accessory ON, power is used from the system, voltage is lowered, and the regulator restores voltage by causing the alternator to make more power. This action automatically allows the alternator to provide power for the electrical system.

The system does not need as much power output from the alternator when accessories are not using power, and when the battery is fully charged. When voltage at the system rises to about 14.2 volts, the voltage regulator begins limiting alternator output. When we switch an accessory OFF, use of power from the system is less, voltage quickly rises, and then the regulator will cause the alternator to make less power.

Adjustment of alternator output, by the voltage regulator, happens so quickly that when using a meter to test the system, we see function as smooth and constant. Even the old points type mechanical regulators could open and close the points over 200 times per second! Electronic voltage regulators have replaced the old vibrating point type regulator, and electronic regulators react even faster. With a modern electronic voltage regulator, voltage at the system will be very consistent.

The battery serves as a big cushion in the system, which also smoothes out voltage level. The battery will provide momentary surges of power, which are needed when devices are switched ON. The battery also can absorb momentary excess of power in the system as devices are switched OFF. The battery prevents major and sudden voltage changes in the system.

THE METHOD USED TO ADJUST ALTERNATOR OUTPUT

The voltage regulator adjusts alternator output by controlling the amount of power it will send to the magnetic field winding in the alternator. (Alternators work through the use of magnets.) More power delivered to the magnetic field winding in the alternator will produce a stronger magnetic field, which causes the alternator to produce more power output. Alternator output is reduced when the voltage regulator delivers less power to the magnetic field winding in the alternator, as the strength of the magnetic field will be reduced.

WHY 14.2VOLTS, BUT WE CALL IT A “12 VOLT SYSTEM?

The 14.2volt level is said to be the ideal voltage level for the “12volt automotive system” because that’s the amount required to fully charge a standard “twelve-volt” battery. By itself, without a battery charger, and without cables connected, a typical, fully charged “12volt” battery produces 12.6 volts. The on board charging system must exceed the 12.6 level for electrical current to flow through the battery during charging. Electrical current must flow through the battery during charging to cause chemical reaction between the liquid acid and the lead plates within the battery. The 14.2volt level causes about the correct amount of current flow through the battery to maintain a fully charged condition. Extended periods with higher than 14.2volt level will over-charge the battery (at most temperatures).

BATTERY CONSTRUCTION and Operating Functions

(The battery interacts with the charging system.)

There are positive and negative metal plates within the battery, each made of different materials, and with insulators between the plates. Liquid acid within the battery (sulfuric acid) is in contact with the plates, and the acid will chemically react with material at the plates to produce electrical power. When the battery is called upon to produce power, as with engine starting, the chemical reaction activity is greatly increased. When the battery is stored, very little chemical reaction takes place, however the elements are waiting in reserve and available for use at any time.

The battery must produce current for engine starting, and the battery may also be called upon to supply power at times when the alternator cannot keep up with electrical system power use. When we connect an electrical device to the battery, chemical reaction takes place to deliver electrical power. Throughout these periods when the battery must supply electrical power, the battery is being discharged.

During discharge of the battery, chemical reaction will produce electrical power. And the chemical reaction between the acid and the plates will convert material at the surface of the plates to a new compound. And as the chemical reaction changes the composition of materials in the battery during discharge, material at the positive and negative plates will eventually become the same. When sufficient material at the plates has been converted to the same material at the positive and negative plates, the assembly can no longer produce adequate power. Then the battery is considered discharged.

Chemical reaction “takes apart” existing material, and reassembles the original ingredients to form a new material. The basic “ingredients” will all still be in the new material, but after the chemical reaction has taken place, the new material will be a different compound. (It happens with manufacturing of plastics and polymers and many things that we use and enjoy.)

By applying energy to the new material, at least some chemical reactions can be reversed, and the new material will be converted back to its original form. This reverse operation is exactly what happens when “recharging” a battery. When recharging a battery, we apply electrical current (energy), in reverse direction, which will cause the chemical reaction needed to change materials in the battery back to their original form. (Back to different materials at the positive and negative plates.)

BATTERY CHARGING

With recharge, chemical reaction changes compounds at the positive and negative metal plates back to their original material. Electrical current will flow through the metal plates in reverse direction during charging, which causes a reverse chemical reaction (compared to discharge). When the battery becomes “charged,” the compounds at the positive and negative plates in the battery will once again be different. With material at the plates restored back to original compounds, the battery is again able to deliver electrical power.

To recharge the battery, we apply electrical power to the battery. The amount of activity with chemical reaction during battery charging will change according to the amount of electrical current flow through the battery. With voltage at proper level, the battery will only accept the amount of current required for reasonable activity with the chemical reaction.

To little current flow will not cause enough activity with the chemical reaction to completely charge the battery. We need sufficient activity with the chemical reaction to change the compounds at the plates back to their original material. Lack of sufficient activity with the chemical reaction resulting from too little current flow may be termed as an “under-charge” condition.

The speed of activity with the chemical reaction during recharge is of great concern! The amount of activity is controlled by the amount of current flow during recharge.

Excessive current flow during battery charging may be termed an “over-charge” condition–the excessive current flow causes too much activity with the chemical reaction. The amount of activity with the chemical reaction must be precisely controlled, and the perfect charge rate is a thin line. It’s a situation where too much charge rate is damaging, but with not enough current flow the battery performance will deteriorate.

It turns out that during charging, the amount of current flow through the battery can be adjusted by regulating the level of voltage as electrical power is applied to the battery. When electrical current is supplied to the battery at proper voltage level, the battery only accepts the amount of current flow it wants. And it’s current flow during charging that will adjust the rate of chemical reaction activity within the battery. The operation is summed up as “charge rate.”

In summary of charge rate, voltage level will adjust the amount of current flow, and the amount of current flow will affect the rate of the chemical reaction. And so with the alternator system serving as the onboard battery charger, the regulator will control voltage, and the rest will follow.

It’s all quite simple, however, the ideal amount of charge rate will change with conditions. (There is always something to complicate matters! Ha!) Battery state-of-charge condition, temperature, and the duration of the charge (either long drives or short drives), are all factors that will determine the ideal charge rate. The discharged battery does not produce as much voltage as the fully charged battery. When charging a “low” battery, the discharged battery will accept a large amount of current flow, if power is delivered at the full 14.2volt level. Ideally, the voltage level would be slightly reduced when a battery is accepting peak amount of current during recharge. Current flow would then be optimized, which will cause the correct rate of chemical reaction. Then charge rate could remain optimized if voltage could be slightly increased as the battery regains charge. Eventually voltage must be limited as the battery becomes fully charged, and then very little current flow through the battery is required.

When primary conditions are short drives in extreme cold weather, the charge rate should be increased. Internal resistance at the battery will change with extreme cold. This and other effects of the cold will contribute to slower charge rates in cold temperatures. Short drives with a slow charge rate may not allow the battery to reach a fully charged condition in extreme cold. The ideal voltage regulator setting should be slightly higher for this type of usage.

The author has lived in cold climates, and also where it is hot much of the year. The hot weather is hard on batteries! In the hot climates, batteries typically have a much shorter life. Also expect to find more corrosion at the battery area with hot weather conditions (because the warm battery “accepts” current at a higher charge rate).

The voltage level must be precisely controlled during charging to prevent excessive current flow. Excessive current flow can damage the battery. Excessive current flow is less efficient because compounds at the surface of the plates will not have time to disperse. Also excessive amount of corrosive and very explosive gas will be produced with over-charge rates. And excessive charge rate heats the battery, which changes internal resistance of the battery.

Especially with “sealed batteries,” over charging will destroy usefulness of the battery! H2O (water) is one of the compounds formed with the chemical reaction during battery charging. Many of the so-called “sealed” batteries are actually vented to surrounding atmosphere, at least one very popular model of battery has a pressure relief valve for venting. The valve allows this popular model of battery to be mounted in various positions. However, these battery are “sealed” with regard to access for adding water. When these “sealed” batteries are charged at a high rate, water and vapors will escape from the vents. And we do not have opportunity to add more water to this type of battery, when the liquid level becomes low. When we allow high rate charging, the “sealed” battery can loose liquid that we cannot replace!

Also, when charging these “sealed batteries with pressure relief valve” at a rate high enough to cause the valve to release; expect severe corrosion problems at the battery area resulting from corrosive liquid and vapors that will spew from the relief. Unfortunately, the author has seen a few cars where this unpleasant experience has occurred. (Every case was with expensive, high end, occasionally driven cars. And in every case the car was also equipped with a high output “ONE-WIRE” alternator, which was connected directly to the battery with a heavy cable.)

VOLTAGE REGULATOR LIMITING

Most important of all, when a battery reaches fully charged condition, then voltage must be precisely controlled, as forcing a charge by allowing voltage to rise above ideal level will result with all the previous mentioned problems. (That applies to all batteries.) And with extended periods of driving, all of the previous mentioned problems will happen for longer time duration. Corrosive vapors emitted from the battery during charging settle upon everything near the battery, resulting with severe corrosion at the battery area. (And I hate when that happens with a nice Hot Rod! Ha!)

Undercharge causes short battery life, and poor performance from the battery. During charging the chemical reaction cleans the surface of the lead plates within the battery. But insufficient charge rate (undercharging) allows a crust of lead sulfate compound to accumulate on the surface of the plates. (This happens even more so when storing batteries in a discharged condition.) The crust will block access of the acid to the active materials in the lead plates, and the crust also changes internal resistance at the battery. With too much crust build up the battery will no longer be serviceable.

It’s a thin line between not enough voltage at under charge and too much voltage at overcharge. And ideal voltage level is different with various conditions. A good voltage regulator is a precisely operating piece of equipment! (And the author prefers and uses exclusively genuine Delco voltage regulators. The genuine item is more costly than some others, but it has a lot more electronics within. The Delco regulator is temperature compensating, it does an excellent job of trimming off charge rate, it has built-in back-up circuits, and voltage limiting is precise. Batteries last longer, and expect less corrosion problems when using the Delco regulators.)

“12VOLT ELECTRICAL PARTS ARE ACTUALLY 14VOLT PARTS!

With most applications, the battery likes about 14.2 volts from the alternator and voltage regulator system, when driving. Since the system must operate at about 14volts, electrical parts are designed for best performance and longest life when operating at about 14 volts. The parts can generally withstand 15volts (or more), although sometimes parts run hot or don’t last as long at stress level voltages.

PERFORMANCE

Although we always aim for the best, we are always likely to loose at least a small amount of voltage with long wiring circuits. What really puts the hurt on performance is low voltage. It turns out that with voltage about 10% low, performance may be down by over 30%. Electric motors, lights, ignition coils, and various parts will all behave differently, but it’s great when we connect the voltmeter with the part powered-up and running, and find about 14volts at the part.

Voltage drop at wiring will only occur during current flow, therefore testing must be done with the part connected, powered-up, and operating. In example, unplugging a wire connector at a part, and then reading voltage at the wire harness connector is not a valid test of circuit performance.

The voltage test while a system is operating is the industry standard electrical performance test. It’s also very simple to do an approximate performance comparison of parts running at low voltage to parts running at full voltage, using only an ordinary car. In darkness, with the engine running and headlights ON, switch the ignition OFF while the headlights are left ON. Notice that the lights dim considerably when the engine stops, as the alternator will also be stopped and voltage drops about 10%. Or with radiator fans running, switch the ignition OFF and notice the fans slow down.

The significance of engine running and engine stopped, is that when the engine is running the alternator will have opportunity to maintain the system at about 14.2volts. But with the engine stopped the battery will deliver power at about 12volts. This simple comparison with engine running and engine stopped serves to give us a general feel for the loss of performance we can expect with parts operating at slightly low voltage. In general, voltage drop at the wiring, with delivery of power to parts, is the enemy to overcome.

THE WRENCH IN THE WORKS!

It all seems so simple just to use a quality voltage regulator built by a major company that has the overall picture all “scienced out.” And install an alternator with more than enough power rating to handle all the electrical loads on the car. But in the world of automotive wiring, voltage drop resulting from long lengths of wire often prevents delivering power at full voltage level to all parts of the system. And especially with our older cars, as with favorites from the Muscle Car period, voltage drop in wiring is a lot worse than most people would guess. The problem often exists with design of the system, not with age and deterioration of the wiring. It happened when these cars were new, and it happens when a new factory harness with the same original design is installed.

So if voltage throughout the system is not the same at all points, then we have a major problem with attempt to use the voltage regulator to optimize performance! The voltage drop only occurs with current flow. Large amounts of current flow through a wire will result with large amounts of voltage drop. If current flow through a wire is reduced, then resulting voltage drop will also be reduced.

If we wire the voltage regulator to read and make adjustments to the lowest part of the system, then the highest part of the system might be dangerously high. It would be safer and in better judgment to wire the voltage regulator to the highest part of the system, but then low voltage will cause poor performance at some systems, and the battery might not even charge properly.

The best option will be to work with design of the wiring layout, when making improvements to electrical systems! (The “improvements” include more powerful alternators, and modern accessories to make good use of the electrical power.)
THE BEST PLAN

The best plan for most systems is to route alternator power output to a central power distribution hub. Then send power from the hub to various parts of the electrical system, and wire the voltage regulator to maintain voltage at the main distribution hub. The idea is very good, but cannot be claimed by the author as an “original.” It happens that Chevy did a very good example of this design with ‘63 through ’71 models. And the Chevy engineers did it well! It’s also a system that we must be aware of when installing more powerful alternators and when installing wiring to power-up new accessories.

See more about this design and function in our Tech Section feature on “REMOTE VOLTAGE SENSING,” and also in our feature on “THE CHEVY MAIN ELECTRICAL POWER DISTRIBUTION SYSTEM.” Also see more about how severe voltage drop actually is with original wiring in our feature on “BRIGHTER HEADLIGHTS.”

 

[grumpyvette]

Disconnecting the battery while the engine is running isn’t a valid test for alternator function and may damage sensitive electronic parts. Instead, use a common voltmeter and the following test procedure. Although some of the steps reference typical GM alternators, the basic methodology is valid for any charging system.

https://www.jegs.com/i/JEGS/555/10308/10002/-1

ford remote starter relays can be used in many higher amp fan circuits

01
Test voltage across the battery terminals with the engine running. A good alternator should maintain battery voltage between 13.9 and 14.8 volts (14.2 is optimum). Even worst-case, with all accessories turned on, there should be at least 13 volts at the battery. Be sure that the engine is running at a high enough rpm for the charging system to function (especially if running a one-wire alternator excited at a specific rpm). If voltage is low, go to Step 02. If voltage is over 15 volts, go to Step 05.




02
Connect the voltmeter between the alternator’s output (BAT) terminal and Ground. If voltage is 13.6–14.6 volts, the alternator is OK, but power isn’t getting to the battery. Go to Step 03. If voltage is under 13.6 volts, go to Step 04.




03
Check the battery cables and alternator charge-wire for bad connections, improper cable and wire size, or corrosion. Repair or replace as needed. Recheck as per Step 02. If voltage is a constant 13.6–14.6, the problem is solved. If voltage is normal, but slowly decreases, go to Step 04.




04
Check the alternator drive-belt. Adjust its tension or replace as needed. On a street car, the crank pulley should be three times larger than the alternator pulley; fix as needed. If voltage is normal but slowly decreases after these repairs, your alternator is OK but can’t keep up with the vehicle’s current demands; upgrade to a higher-output alternator. If you get an immediate under-13.6 volt reading, go to Step 05.






05
Test the voltage regulator. For external regulators, go to Step 06. For internal regulators, go to Step 07.




06
Unplug the harness from the regulator. With the engine running, connect a jumper wire from the connector’s B+ Terminal to the connector’s Field terminal (on most GM cars, that’s respectively the red and blue wires). Only do this for 30 seconds at a time. The engine will bog down. The alternator should have an audible whir and ramp up to max output. If you see a visible arc, repair or replace the regulator. If there’s no arc, the alternator has an open Field circuit or worn-out brushes. Fix or replace as needed.




07
GM SI alternator internal regulators can be checked as shown in the photo. If voltage goes up during this check, repair or replace the internal regulator. If voltage is lower than before, repair or replace the entire alternator. Late-model GM CS alternators don’t have serviceable regulators; the entire unit must be replaced.

Read more: http://www.hotrod.com/how-to/engine/1402-faulty-alternators-quick-test/#ixzz3ZDiGlAph
Follow us: @HotRodMagazine on Twitter | HotRodMag on Facebook

 

[Grumpy]

AF_Donposted this info


1: Your First Test - Measure Battery volts

Many meters are inexpensive because they require you to manually select the correct measurement and range for the test you want to do. More expensive auto-ranging meters are available to handle range selection. All car batteries provide DC (direct current) voltage, most often in the range of about 10 to 16 volts.

Look at the face of the meter and turn the handle to select DC volts, with a maximum range of 20. Other choices may include 2 or 200 DC volts. You could harm an inexpensive meter by selecting 2 volts, if it doesn't have over voltage protection. Choosing the 200 volt range won't blow anything up, but you won't get a useful reading.

The two probes that came with the meter are red and black. Red is always for the positive terminal and black for the negative, or ground, post when doing voltage readings. With the engine off and the key out of the ignition switch, touch the black probe to the ground post and the red probe to the positive post. The meter should instantly display a number, which is the battery voltage.

Expect to see something in the range of 11.5 to 12.6 volts. Anything less than this may indicate a bad cell in the battery, or one requiring water if it is not maintenance-free (unusual these days).


2: Really Important Simple Test - Ground Resistance




The next test could save you hours and hours of messing around, particularly on older vehicles. Modern car electrical systems use a 12 volt, negative ground configuration. This means that electricity is supplied from the positive terminal on the battery, while the negative terminal is connected to the car body and chassis.

This works well so long as the body and chassis are metal. It also works well as long as the body and chassis are electrically connected, usually by a ground strap or fusible link. Checking the resistance between various points on the body, engine and chassis will ideally show no resistance. This allows continuous flow of electricity and is called a continuity check.

Resistance is measured in ohms, so we're going to set the meter to its lowest resistance range to do our tests. With that done, touch the red probe to the negative terminal on the battery. Yes, I said the black goes to the negative last time, but we're not measuring volts any more.

Now, touch the black probe to some bare metal on the engine. The exhaust manifold is often a good place. Your meter should display a zero for the resistance value. It may also beep or flash a light, depending on its design. If it doesn't display zero or some very low value, check the connection between the battery's negative cable and the body or engine.

Follow the black cable from the battery to its destination. Look for a corroded or loose terminal. Look for a ground strap that connects the body and the chassis or subframe. The body is mounted on rubber isolators to keep the cabin quiet, but rubber is an insulator. A direct electrical connection is established using a flexible metal strap. Check the ground strap for corrosion, loose connections and overall good condition. Clean and tighten the connections, and/or replace the ground strap as needed.


3: Next Up - Cranking Voltage Test



You may need more than one pair of hands to do this, so if someone is around ask for their help. Even if the battery showed a good voltage in the first test, it may be worn internally and barely able to supply enough juice to start the car reliably.

Before anything else, make sure that the battery terminals are clean and the connections are tight and secure. Do the same for the starter motor and the starter solenoid connections. Now, we want to disable the ignition system so that the car won't start when we crank it.

On older cars, you can do this by disconnecting the ignition coil - either the high voltage wire going to the distributor, or preferably the low voltage positive (red) wire going to the coil. For electronic ignition, refer to the car's manual on how best to do this. You may need to disconnect the distributor pickup coil, or a crankshaft or camshaft position sensor.

Set the multimeter's range and connect it to the battery as done in Test 1. If you have a remote starting switch, use it or else have someone try to start the car for about 15 seconds. Watch the voltage displayed on the meter. The following chart shows the best result for the current temperature. What you saw on the meter doesn't correspond with these results, then you have a problem.

Temperature -> Volts
70F+/ 21.1C+ = 9.6 or more
60F / 15.5C = 9.5
50F / 10.0C = 9.4
40F / 4.4C = 9.3
30F / -1.1C = 9.1
20F / -6.7C = 8.9
10F / -12.2C = 8.7
0F / -17.8C = 8.5

If the previous step went well, or you cleaned up all the connections, the current problem lies either with the battery, starter motor or solenoid. You can take the battery to a shop to have a load test done. Further checks of the starting system are possible, but are beyond the scope of this article. Check the manual that came with your meter for more information that may help.

4 - Charging System Test


To see if the vehicle's charging system is healthy, set up and connect the meter as we did in Test 1. Start the engine and let it idle. Turn off all electrical loads, such as the stereo, fan, lights, defroster and so on.

On the multimeter, you should see a value between 13.2 and 15.2 volts. Values lower than this may indicate loose or corroded connections, a loose drive belt or a mechanical problem with the alternator. Higher readings are most likely due to an electrical problem with the alternator.

If you're good to this point, have someone sit in the car and run the engine up to 2000 to 2500 rpm and hold it there. Check the reading on the meter. It should not have changed by more than half a volt from the previous reading.

Now, have them turn on as much electrical load as you can. With the fan, lights, rear defroster and everything else running, the battery voltage should not drop below 13.0 volts. If you have installed a high end audio system, leave it off at first. If the voltage is at 13.0 or higher, but drops below when the audio system is on, it is drawing too much power and you need to upgrade to a higher output alternator.

5 - More Continuity Tests




The ground resistance test we did earlier is a special application of the Continuity test, which checks for a continuous connection between two points or electrical terminals. This is a very basic and also very handy test.

For example, you can verify the state of a fuse with a continuity test. If the resistance between the fuse's terminals is zero or very close to that, then the fuse is good. If the resistance cannot be measured because it is too high, then the fuse has blown and there is no continuity between the terminals.

The same thing applies to high voltage ignition wires. These will have some resistance to them. Just check the manufacturer's literature for the value. If you can't find that, then just keep the average value in mind as you go along. Touch one probe to each end of the ignition wire to measure the resistance. Wiggle the wire and see if any big changes in the resistance happen, which would indicate a loose connector or perhaps a break in the wire. If all wires but one have a similar resistance value and one is significantly higher, the oddball wire probably is defective.

Checking a mechanical switch is just about as easy. After disconnecting the wiring harness plug,touch one probe to each of its two terminals. Then actuate the switch manually. You should see the change. A normally open switch will show infinite resistance until you actuate it, then it should show zero resistance. A normally closed switch will show the opposite. If it doesn't change, the switch is shot.

 

[Grumpy]

Top Ten Multimeter Tests - Part 2 of 2 AF_Don posted this info
(Continued from Part 1)

6 - More Resistance Tests

You can apply the same test to a number of other components that could be stopping your ride. For example, anything that uses a coil - ignition coils, solenoids, injectors and most sensors - should read only a low resistance between the power and ground terminals. A coil, after all, is just a spool with a lot of wire wound around it. If the wire has been broken, there is no continuity between the terminals and the coil cannot do its job.

Coil-on-Plug (COP) ignition coils can be checked individually. The best approach here is to test the coil resistance when everything is cold. Look for look for open circuits (infinite resistance) or an odd man out. If the car can be run while the low voltage coil wiring is reachable, run the car for a while and then stop. Quickly check the coils again and see if anything has changed significantly. This could help you diagnose an intermittent problem.

If you cannot easily get to the coil terminals with the COPs in the car, you could use an oven or a heat gun to heat them up to about 300 degrees F and check them - carefully - while hot. DO NOT microwave the components!

Another case where you would need to measure resistance would be during the install of a remote starter kit, in a GM vehicle that uses the Vehicle Anti-Theft Security (VATS) system. For the remote start feature to work, you'll have install a resistor in the wiring that matches the value of one that is embedded in the key. To figure out that value, touch the probes to either side of the pellet on the VATS key. With that knowledge, you can find and install the correct resistor.

7 - Engine Speed Test



OK, so you've got a tach inside the car but it's not simple to read when you've got your head under the hood. Hooking up the meter is easy, or a bit harder depending on whether you're dealing with a conventional or electronic ignition system. Some of the following details may vary by the brand of multimeter you're working with, but a little common sense will help get you through the details.

Before hooking anything up, you have to tell the meter about the engine you're checking, specifically the number of cylinders. Most meters have individual dial settings for RPM tests on 4, 6 and 8 cylinder engines. Some might have a separate switch for setting this.

Since most meters also only use a 3 or 3-1/2 digit display, you may be reading tens of RPMs and have to multiply the displayed reading by ten. So, if the meter is showing "215" then the engine is turning at 2150 RPM. Pretty obvious stuff, right?

For vehicles using a distributor, locate the ignition coil and connect the red probe to the negative terminal on the coil. Connect the black probe to a ground source. Start the engine and run it at the required speed. Read the speed from the meter display.

For distributorless ignition systems (DIS), locate the TACH signal wire going between the DIS module and the engine control unit (ECU). You will need to refer to the vehicle's service or technical manual for this information. Connect the meter's red probe to the TACH signal and the black probe to ground. Start the engine and run it at the required speed. Read the speed from the meter display.

8 - More Frequency Tests


In the engine speed test, what the meter was actually reading was the time between signal pulses. Each pulse corresponds to the coil firing. As the engine speeds up, the time between coil pulses gets shorter in proportion to the engine speed. There are other applications for frequency measurement.

Some kinds of MAF (mass air flow sensor) send a frequency signal to the ECU, according to how much airflow is detected. You'll need the service or technical manual for the vehicle to know what frequency range is involved. Not all multimeters have the capacity to handle high frequency signals.

The same can happen for Manifold Absolute Pressure (MAP) sensors, as well as Barometric Pressure sensors. Ford versions do use an output frequency, while those from GM, Chrysler, Honda and Toyota use a DC voltage.

Actually testing these sensors also requires a pressure and vacuum source, typically a hand pump designed for this kind of testing. As as result, we'll not get into the testing details. However, if you need to read any frequency signal, the general procedure is to set the meter to 4-cylinder RPM and test the component. Then, if need be, multiply the display reading by ten to get the RPM value, and finally divide that by 30 to get the frequency in Hertz, or cycles per second.

9 - Battery Drain Test




Cars equipped with onboard computers usually need a continuous source of power to retain information. This puts a small, but measurable drain on the vehicle battery. In normal circumstances, the draw is minimal, however, adding more electronics can increase the drain.




With older cars, about the only thing that draws from the battery, when everything else is shut off, is the clock. It is also possible that some other electric circuit could fail and start pulling power from the battery. The typical result is a no-start condition when you need to get going the next morning.

If you suspect that something in the vehicle is draining the battery, you can measure how much power is being taken from the battery when everything is off. You will need to disconnect the positive cable from the battery. If there is a hood light, take the bulb out, so that you're not measuring the draw from that. Close the trunk, doors and turn off any other electrics that might be running.

In this test, you'll be measuring current, as opposed to voltage. Current is measured in Amps (Amperes, actually) and the meter will have a fuse to limit the current flow through it. Too much current will blow the fuse, so for convenience always start at the highest level the meter is capable of... usually 10 amps. We're actually expecting a result less than 200 milliamps, but if you don't have a spare fuse, do it this way the first time.

Touch the black probe from the meter to the positive cable and the red probe to the positive terminal post on the battery. You shouldn't have any draw that the meter can measure in this range. If so, switch the meter down to the next range and try again. A current drain of a few or tens of milliamps (thousandths of an amp) can be expected on a modern car to keep the ECU memory alive.

If you read significantly more than this, you may have a problem somewhere in the car. You can try to isolate the problem area by leaving the meter connected and pulling fuses one-by-one from the fuse box. If the draw level drops when you pull a fuse out, check what equipment that circuit is for. The problem is likely to be in that area.


10 - Temperature Measurement



Some multimeters come with temperature measurement capability. This is most often done using a thermocouple wire that plugs into the meter. A thermocouple is made from two wires of different metal. Those materials are chosen so that they actually produce a small electrical signal when in contact with each other. Even more handy is that the voltage produced changes with the temperature at the junction of the wires changes.



There are different types of thermocouple, depending on the metals used. If your meter came with a J-K type thermocouple (probably the most common for general use), you cannot use a different type. The specific performance of the thermocouple is programmed into the meter in order to give you a reading in degrees, rather than volts.

To measure the temperature of something, set the meter to read temperature in either farenheit or celcius degrees. Check if there are any range selections available and, if so, choose the appropriate one. Plug the thermocouple socket into the meter and touch the bare end to what you want to measure. Do take appropriate personal protective measures if working near high temperature components, so that you don't burn yourself.

You can hold the insulated wire (gently) with a pair of pliers without significantly affecting the reading. Thermocouples will often show an error range up to two or three degrees. You can check the accuracy by touching the tip to an ice cube, which should read about 32 degrees farenheit (0 deg Celcius). After, immerse it some boiling water. This should read about 212 degrees farenheit (100 deg Celcius). If you're not within a couple of degrees for each of these, check for damage of the wire, insulation and weld bead at the tip. Make sure that the tip is clean.

You probably got a three foot long thermocouple wire, which is handy for general work. Thermocouples are common industrial items and are available in a range of lengths. With a longer one, say 80 inches (a common size), you could measure intake air temperature on the road by putting the tip into the incoming air stream and running the wire back to the passenger compartment where the meter can be protected and seen easily.

There are many other possibilities, with the biggest challenge only being how to keep the thermocouple tip reliably in contact with the component of interest.

Dealing with Older Vehicles

I can tell you from experience that the most challenging electrical problems that you're likely to encounter in older vehicles result from either a lack of power or a lack of ground. Neither of these problems can be solved by just replacing components and hoping that the new one works.

Of the two problems, the lack of a good ground is more likely than a lack of power. Power problems usually come from a broken or cut wire. Ground problems most often result from corrosion. If you've ever seen another car's tail lights acting funny - for example, alternately blinking the signal and brake lamps - this is a sure sign of a ground problem.

You only need to do two things to diagnose most any electrical problem. First is an understanding of how the circuit of interest works. For example, a radio needs power, ground and a good signal from the antenna. If it isn't getting all of these, it won't work well, or at all.

The second thing is to take that understanding and break it out into a series of simple steps to check. Is the radio getting power? If not, why not? Is there continuity between the radio case and vehicle ground? If not, why not? In general, if there is no power, check the fuses first. If there is no ground, try running a separate ground wire from the radio case to a known good ground.

If there is power and ground, does the front panel light up? If not, the radio is likely dead. Is the antenna is good condition? Is the cable from the antenna plugged into the radio? Is there any evidence of damage to the cable? Does reception improve if you plug in another antenna? Answering these questions will bring you to a logical conclusion.

You may be looking to upgrade anyway, but its always good to know that you're not throwing good stuff out.

Dealing with Newer Vehicles

Modern vehicles are becoming more sophisticated in all aspects, including their electrics. Charging blindly into the wiring of your car or pulling components out for random checks isn't really the best way to approach things. Stick to the simple stuff unless you have the appropriate diagnosis and repair manuals. You will likely need much more sophisticated tools than the simple multimeter that we've been dealing with.

A better approach is to borrow or buy an OBD II code reader. Modern vehicles have On Board Diagnostics (OBD) and run diagnostic checks regularly. Problem issues are logged and may trigger a check engine light (CEL) or other warning indicator. The code reader can retrieve this information from the car's diagnostic system. What it tells you may give you an idea of how best to proceed.

For now, stick with the basics. If and as you get comfortable with how things work from the electrical side, you may want to take on greater challenges. Succeed at these and you'll be unique in the hobby. Even if you don't move beyond the basics, you're likely to save yourself a bunch of money and keep your ride on the road, instead of in the shop.

http://www.corvettemagazine.com/2001/oc ... y/bat1.asp

 

[Grumpy]

the first thing ID check is the battery cable connections and grounds to the frame and the alternator output at the alternator , then the ohms resisitance in major battery cable connections

cars use DC homes use AC current ,know the difference and use the correct meters

http://garage.grumpysperformance.co...urrent-flow-grounds-and-more.3504/#post-54625

http://garage.grumpysperformance.co...hooting-tip-for-electronics.11317/#post-51557

Measured Value

Engine Coolant Temperature Sensor. 185 Ohms @ 210F, 3400 Ohms @ 68F, 7,500 Ohms @ 39 F.
Engine Oil Temperature Sensor. (lower sensor above oil filter) 185 Ohms @ 210 F, 3400 Ohms @ 68 F, 7,500 Ohms @39 F.

some early c4 vettes have the gauge and oil pressure switch on an adapter near the distributor base into the block

to add something to this that is often over looked regarding MAF codes, so here it is, a direct quote from my 87 FSM which is probably the same for 85,86,88,89.

Second paragraph on both code 33 and 34...interestingly not on code 36.
Code 33 page 6E3-A-42

"The oil pressure switch or the ECM, through control of the fuel pump relay, will provide 12 volts for the MAF power relay which provides the 12 volts needed by the MAF sensor".
I personally know a few guys who cured their MAF problem simply by either replacing the FP relay or repairing the wires going into the FP relay...these wires over time may have had the insulation shrink back (mine were bare 1-2 inches, and touching) not only dangerous , but can cause all types of problems.

Oil Pressure Sender/Switch. (top sensor in picture above) 1 Ohms @ 0 PSI, 43 Ohms @ 30 PSI, 86 Ohms @ 60 PSI.
Fuel Quantity Sender. 0 Ohms @ Empty, 45 Ohms @ 1/2 Full, 90 Ohms @ Full.
MAT (Manifold Absolute Temperature Sensor). 185 Ohms @ 210 F, 3400 Ohms @ 70 F,
http://www.amprobe.com/Amprobe/usen/Contests_Promotions/amp-25.htm?gclid=CJGbirzF59ACFUU2gQodJ6UIqA

http://www.powerstream.com/DC-clamp.htm

https://www.amazon.com/Amprobe-AMP-...1481301013&sr=8-9&keywords=fluke+dc+amp+meter

http://en-us.fluke.com/training/tra...-digital-multimeter-plus-clamp-accessory.html

theres little sense in even having a relay in a car that won,t operate at a minimum of 12 volts and at least 30 amps minimum,
but Id have to point out that matched sets of relays and pigtails are readily available in several amp ranges rather cheaply.
once you understand how they are designed to function testing or replacing one is no
challenge

https://www.amazon.com/ARTGEAR-Harness-Color-Labeled-Automotive-Motorcycle/dp/B078T3RC5T

https://www.summitracing.com/parts/pco-5593pt/overview/

https://www.amazon.com/Fastronix-Weatherproof-Automotive-Relay-Socket/dp/B01CXA42XK

https://www.ebay.com/bhp/60-amp-relay

https://www.ebay.com/bhp/80-amp-relay

http://www.autoswitch.com/relays.php

https://www.summitracing.com/parts/...MIq4ObtvSz3wIVU57ACh0MfQn4EAQYAiABEgJsYfD_BwE

https://www.amazon.com/dp/B07F83159...&pd_rd_r=991c9f49-060a-11e9-bb5a-dff16524fffe
some related threads that should help
http://garage.grumpysperformance.co...ing-down-an-electrical-drain.8493/#post-37179

http://garage.grumpysperformance.co...tting-out-low-voltage.12221/page-2#post-59599

http://garage.grumpysperformance.com/index.php?threads/testing-an-alternator.3222/#post-46703

http://garage.grumpysperformance.co...lternators-and-oil-all-here.12628/#post-64603

http://garage.grumpysperformance.com/index.php?threads/how-altenators-work.355/#post-62266

http://garage.grumpysperformance.co...uys-don-t-look-at-the-clues.11176/#post-50125

http://garage.grumpysperformance.com/index.php?threads/suspicious-voltage-drop.10718/#post-46927
BTW FAULTY GROUNDS, IN MANY CARS AND ESPECIALLY NEWER CORVETTES CAUSE MANY ELECTRICAL ISSUES SO IF YOU HAVE INTERMITTENT ELECTRICAL ISSUES CHECK THEM CAREFULLY

LCD dash ground is behind drivers kick panel . There are also several electrical grounds down just above the oil filter and one behind the passenger kick panel for the ECM. and a couple on the rear of the drivers side cylinder head, Grounds are a constant issue on most c4's. Hope this helps.
TYPICAL ACCESSORY CURRENT DRAW (AMPS)
Lights
Headlights (high beam)40
Headlights (low beam) 10-22
Tail Lights 8
Safety
Emergency brake light 4
Emergency flasher 15
Turn signals 10-15
Windshield wipers 6-20
Horn 15
Brake lights 15-20
Running lights 8
Ignition
Winter starting 225-500
Summer starting 100-400
Approx. Avg. 300
Courtesy
Cigarette lighter 15-20
Interior lights 10-15
Instrument panel lights 4
Entertainment
Radio 10
Stereo Tape 10
Electric antenna 20
Comfort
Air conditioner 10
Heater 20-30
Defroster 15-30
Electric seat 20
Electric windows 20-30
TYPICAL ACCESSORY CURRENT DRAW (AMPS)

Typical Current Loads for Automotive Systems, Lighting and Accessories:
Engine Idling (no lights or accessories on) - 35 to 50 amps. This will vary depending on the number of cylinders (more cylinders draw more power for the fuel injectors and coils), the type of fuel injectors (some draw higher amp loads than others), the type of ignition system (single coil or multi-coil), the amp draw of the PCM, and the fuel pump (the amp draw will be higher with higher pressure systems).

Engine Off (nothing on) - 40 to 50 milliamps (power drain by modules in sleep mode, antitheft system and keyless entry)

Ignition Coil (single oil-filled coil older vehicle) - 3 to 4 amps.

Ignition Coil (single DIS coil newer vehicle) - 5 to 6 amps.

Ignition Coil (coil-on-plug) - 6 amps per coil.

Ignition System (primary circuit) - 6 to 20 amps.

Fuel Injectors - 4 to 6 amps peak, 1 amp hold

Electric Fuel Pump (depends on pressure and flow) - 4 to 12 amps

Electric Cooling Fan (depends on size) - 6 to 30 amps

Headlights (halogen low beam) - 8 to 9 amps per pair

Headlights (halogen high beam) - 9 to 10 amps per pair

Headlights (halogen high and low beams combined) - 17 to 19 amps

Headlights (High Energy Discharge) - 12 to 14 amps during initial start, 7 to 8 amps once bulbs are hot

Headlights (LED) - 0.6 to 1 amps per bulb

Small bulbs (incandescent) - 0.3 to 0.4 amps per bulb

Small bulbs (LED) - 0.04 to 0.06 amps per bulb

Starter Motor - 200 to 350 amps

500 Watt Sound System - 42 amps

Electric Rear Window Defroster - 10 to 20 amps

Windshield wipers - 2 to 10 amps depending on load

Heated Seats - 3 to 4 amps per seat

Power Windows - 3 amps

Electric Power Steering - 2 to 40 amps depending on load

Air Conditioner Compressor Clutch - 2.5 to 5 amps

Heater A/C blower motor (depends on load, size and speed setting) - 2 to 30 amps

related info

HAVING A HIGH AMP (160-220 amp) QUALITY ALTERNATOR AND A DECENT BATTERY, WITH GOOD CLEAN CABLE CONNECTIONS HELPS IMMENSELY
http://www.summitracing.com/parts/tff-8173nep/applications/year/1996

http://www.summitracing.com/parts/tff-8173nep/applications/year/1996

http://garage.grumpysperformance.co...ing-down-an-electrical-drain.8493/#post-37179

http://garage.grumpysperformance.com/index.php?threads/heat-shrink-tubing.1443/#post-3211

the threads have links youll need

http://garage.grumpysperformance.co...-auto-elecrtrical-connectors.3105/#post-68805

http://garage.grumpysperformance.co...trical-wiring-for-a-tbucket.10038/#post-39056

http://garage.grumpysperformance.co...vious-owner-butchered-wiring.3439/#post-19529

http://garage.grumpysperformance.com/index.php?threads/lots-of-wiring-info-diagrams.317/#post-84479

http://garage.grumpysperformance.com/index.php?threads/testing-an-alternator.3222/#post-46703

http://garage.grumpysperformance.co...urrent-flow-grounds-and-more.3504/#post-33363

http://garage.grumpysperformance.co...r-auto-elecrtrical-connectors.3090/#post-8220

http://garage.grumpysperformance.com/index.php?threads/heat-shrink-tubing.1443/#post-28050

 

[Grumpy]

If you,ve ever spent 20 minutes to an hour with a multi meter tracking down an intermittent electrical issue,
only to find some previous "genius" physically wrapped a wire connection ,
without bothering to clean and solder the connection,
or use heat shrink tube to insulate it..
only to find it corroded and loose , you know how frustrating dealing with sloppy and lazy previous wire work can be...
if its in need of repair, take the time and effort to buy a new pigtail connector,
or wire splice and solder it in place correctly,
read through and use the info in the previous posts

www.batterycablesusa.com

https://ceautoelectricsupply.com/
https://www.hagerty.com/media/maintenance-and-tech/understanding-relays-part-3/

you really need decent quality basic tools

https://www.homedepot.com/p/DEWALT-Compound-Pliers-3-Pack-DWHT70485/204413745?cm_mmc=Shopping|G|Base|D25T|25-1_HAND+TOOLS|NA|PLA|71700000034127224|58700003933021546|92700031755124811&gclid=EAIaIQobChMIioKx-pb-4wIVgx6GCh0GVw8uEAQYAiABEgIaEvD_BwE&gclsrc=aw.ds

https://www.amazon.com/Stripper-Ele...DQVE5KS4TNC1KHEF6&qid=1565641631&s=automotive

https://www.amazon.com/Gardner-Bend...strip+tool&qid=1565641582&s=automotive&sr=1-2

if you had a c4 corvette this might also help

tracking down the problem getting the engine started​

If your car won,t start consistently, you need to isolate the problem to the source, you can,t isolate the cause without understanding the process, so you may as well start looking into how and why each step in the process starts , and how each step functions and triggers the next step. your...
garage.grumpysperformance.com

1988 C4 Instrument Cluster Has Stopped Working​

have a 1988 C4 that I had to replace the wiring harness and before installing. I made sure all joints were soldered and all wires were good. When finished installing I did not have my instrument cluster. I do have all the idiot light, blinkers, high beams. They bright and dim as they are...
garage.grumpysperformance.com

Relay/s, Voltage Drop/s, Current Flow, Grounds and ... more​

A relay is nothing more than a device that uses a low-current signal to operate a high-current circuit, he solenoid on your starter is a type of relay that uses the low-current signal from your starter switch to operate the high-current circuit between the battery and the starter motor...
garage.grumpysperformance.com

c4 & c5 corvette trouble codes​

if your corvette won,t start or run, don,t panic its usually easy to locate the problems source, buy a CHEVY SHOP MANUAL FOR YOUR YEAR CORVETTE! RULE#1 never assume a damn thing ISOLATE ,TEST AND VERIFY http://www.professionalequipment.com/ex ... ermometer/ Wide temperature range from -58 to...
garage.grumpysperformance.com

cooling off that c4 corvette​

your stock corvette http://garage.grumpysperformance.com/index.php?threads/thoughts-on-cooling.149/page-3#post-107697 has a rather marginal cooling system if your engines been modified for significantly higher hp levels, that cooling system can be significantly improved upon.I run into this...
garage.grumpysperformance.com

https://www.autozone.com/diy/repair...ring-diagrams-repair-guide-p-0900c1528008fd94

CHECK ALL YOUR FUSES WITH A MULTI METER
most electric solder guns are nearly useless,
as they won,t adequately heat wires quickly
the one below is marginally better than most
https://www.homedepot.com/p/Wall-Lenk-400-150-Heavy-Duty-Soldering-Gun-with-Case-LG400C/203457053

the threads have links youll need

http://garage.grumpysperformance.co...-auto-elecrtrical-connectors.3105/#post-68805

http://garage.grumpysperformance.co...trical-wiring-for-a-tbucket.10038/#post-39056

http://garage.grumpysperformance.co...vious-owner-butchered-wiring.3439/#post-19529

http://garage.grumpysperformance.com/index.php?threads/lots-of-wiring-info-diagrams.317/#post-84479

http://garage.grumpysperformance.com/index.php?threads/testing-an-alternator.3222/#post-46703

http://garage.grumpysperformance.co...urrent-flow-grounds-and-more.3504/#post-33363

http://garage.grumpysperformance.co...r-auto-elecrtrical-connectors.3090/#post-8220

http://garage.grumpysperformance.com/index.php?threads/heat-shrink-tubing.1443/#post-28050