starter seems ok but key won,t start car

Grumpy

Grumpy

The Grumpy Grease Monkey mechanical engineer.
Staff member
As you guys know, wiped a few lobes and sheered the crank in my old flat tappet sbc in my 61 Impala. I now have a newly rebuilt oem roller engine and 700r4. I had a problem with my long tube headers burning out the starter due to heat soak. So I replaced with repro 2 1/2" ram horns, and I replaced the jegs mini starter with a sbc 80s starter. Well i drove her today after the muffler shop. I went to turn key and nothing at all. But if I jump the solenoid with a flat head she starts right up. What would cause that? The battery has been dead before due to sitting but I recharged. Oreilly tested the starter and alternator a few weeks ago and said both fine. I have had the ignition switch swapped out, but that was last year. The front and rear wire harnesses are new, but under the dash is all original 1961, I know, I should have replaced but it was scary looking under there, Lol. I have alot of money in this new aluminum headed motor, and she runs great once started, even though we need to verify timing and tweek the 750 carb a bit. I looked at all of the wires, ground and under dash. What do you guys think? Thank you in advance
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Click to expand...


its amazing what a bit of careful testing with a multi meter might do towards providing proven facts that you can use to prove the cause of your problem
don,t guess ,,
NEVER GUESS! DEAL IN VERIFIED, REPEATEDLY TESTED FACTS!
don,t guess ,
verify the starter,
ignition switch ,
neutral safety switch,
and connecting cables
and electrical grounds are good!
THINK LOGICALLY ,ISOLATE AND TEST,NEVER ASSUME!
PULL THE TROUBLE CODES AND USE THE SHOP MANUAL AS A GUIDE,
YOU may be amazed at the number of times a bad sensor or loose wire, bad ground or blown fuse is the problems cause.
I've seen guys rush out and spend hundreds of dollars on parts,too fix a problem, take a great amount of effort to tear apart the dash or other area and once the new parts installed it still won't work, so forced to do further research at that point they only then find a blown fuse or corroded electrical connection.(that was the true initial cause)


viewtopic.php?f=50&t=3110&p=12074&hilit=multi+meter#p12074
image_6238.jpg

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

if the starter is good its rather obvious that the electrical connections or switches are suspect.
image_6238.jpg

use of a shop manual and multi meter can be very helpful
startersolenoid.gif

startermount.gif

this is most likely both the easiest diagram to use and understand
http://garage.grumpysperformance.co...nting-a-battery-in-the-trunk.4395/#post-11556

http://www.novaresource.org/starter.htm

http://www.blackmilkmedia.com/how-to-wire-a-chevy-starter-wiring-diagram/

solenoid04.gif

solenoid06.gif

solenoid07.gif

solenoid05.jpg

http://garage.grumpysperformance.co...lem-getting-the-engine-started.63/#post-31920

http://garage.grumpysperformance.com/index.php?threads/problem-with-starter.1646/

http://garage.grumpysperformance.com/index.php?threads/problem-with-starter.1646/#post-26319

http://garage.grumpysperformance.com/index.php?threads/remote-solenoid-schematic.4846/#post-13266
 
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I suspect the Purple S - wire is faulty coming out of the ignition switch Grumpy.
Best way to test is perform a voltage drop test from S-terminal of starter motor to the backside of ignition switch.
Cranking it should be .1 volts DC or less voltage drop.

Same wire failed on my 1963 Grand Prix back in 1998.
I soldered in a new Purple S-wire.
 
solenoid07.gif


510SH.jpg

startwiredfgg.jpg

This circuit essentially bypasses the voltage drop from the long factory wiring path
from battery, to fuse block, to the ignition switch, to neutral safety switch, then all the
way to the starter S terminal.
By adding the Ford solenoid, the ignition switch circuit now only has to energize that
Ford solenoid (closes A to B), which then applies +12v battery voltage to the GM starter
S terminal in a much shorter path (same as jumping the solenoid with a flat head screwdriver).
In some cases this can work, but it is really telling you that your old under dash
wiring is inadequate and undersized (too much voltage drop).
a quality gear reduction starter,
straitspl.jpg


the better quality versions of the gear reduction high torque starters tend to work rather well
tff-6772b_w.jpg

Tuff Stuff Performance 6772B
https://www.summitracing.com/parts/tff-6772b/overview/make/chevrolet

http://garage.grumpysperformance.com/index.php?threads/problem-with-starter.1646/#post-65015
The best way is as Grumpy suggested below:

startersolenoid.gif
 
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I have been dogged for quite a long time by starter issues. Typically the starter spins up fine as long as it's cold. Sometimes there is a slight hesitation. When hot... it may not come up at all.

This weekend, I am going to break the back of this one. I did notice that the large (+) post on the solenoid housing is not cinched down. The eyelet is tightly sandwiched between nuts but the post itself is not cinched down. That's one thing I'll have to get a look at. The starter is wrapped in insulation so I doubt it is heat sink - possibly in combination with the loose post.

I'll also go through and check all my grounds including voltage drops.

Finally this weekend the weather will be nice enough.

Then - I all need to replace my (puntured) radiator and reinstall some new drag bags.

Stay tuned.
 
Heh and a propos, I just saved a fine young lady the expense of buying a new battery. On her FB she mentioned that her car wouldn't turnover - not even with a jumper cables... Hmmmm. Surprisingly clueless friend after clueless friend chimed in reinforcing that she needed to "buy a new battery".

Turns out it was a loose wire.
 
yeah! its amazing how many people seem to be adverse to the concept of actually testing, and verifying facts, to find out the cause of an issue vs guessing and randomly swapping parts without any facts
 
I just cant do the the Facebook & Twitter thing .
I am a Forum guy Dorian.
 
The bit that surprised me is how quickly people joined in on replacing the battery - I don't know about you guys, but batteries are $$$$.
 
and the funny part is that many times the battery gets replaced and the car runs fine and the owner is convinced it was the battery's fault as a result, when the fact was that the guy replacing the battery at most shops simply doesn,t bother to check the old battery because he only makes MONEY replacing it with a NEW battery, yet the problem was solved when the tech, cleaned the battery terminals and connecting cable contact surfaces before installing the new battery, and it would also have been cured if he had done the same connection clean-up on the cables and battery terminals on the OLD battery.
btw the most common electrically related problem I see on a consistent basis is corroded or badly rusted or defective battery connections and grounds so before you go crazy its a good idea to replace those as a first step in any electrical problem diagnoses
BATERM.JPG

bc1a.jpg

bc2a.jpg

bc3a.jpg

cleaning and coating the battery's terminal connections, cable ends, and electrical grounds, and verifying the connections are correctly tightened, goes a long way toward reducing potential starter/battery issues
batcl1.jpg


batcl2.jpg

batcl3.jpg


ampmeter.jpg

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

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
as always you simply isolate and test in a logical manor to find the cause, random guessing and parts replacement without testing gets damn expensive and your unlikely to randomly guess correctly before it costs you more than it should to correct! ,Id start with having a local auto parts store load test the battery after getting the multi meter out you have , and cleaning all the cable connections carefully and ohms test them
and yes you need a multi meter and if the battery checks out Id be looking at the connections on the starter and the starter itself
http://garage.grumpysperformance.com/index.php?threads/suspicious-voltage-drop.10718/#post-46927

http://garage.grumpysperformance.co...uys-don-t-look-at-the-clues.11176/#post-50124

http://garage.grumpysperformance.co...k-clunk-clunk-start-problem.11422/#post-54990

http://garage.grumpysperformance.com/index.php?threads/battery-charger-for-the-shop.928/#post-1565
 
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can someone tell me the no. of starter for l79 motor
.my starter is a reman.no. ground off.
or maybe a starter off the different motor.
maybe big-block?
Click to expand...

this starter linked below,
should work, why not give them a call,
head-why-shop-1.png

Call (800)753-2242
Ive purchased several starters from them over the years

https://www.dbelectrical.com/search-results/#??Make=CHEVROLET&Vtype=AUTO AND LIGHT TRUCK&Model=BISCAYNE&Year=1972&Enginetype=5.7L(350) V8


http://www.superchevy.com/features/sucs-0732-chevy-l79-engine/




related threads YOU SHOULD READ the links

http://garage.grumpysperformance.com/index.php?threads/under-car-safety.26/

http://garage.grumpysperformance.com/index.php?threads/starter-ring-gear-issues.15323/#post-89687

http://garage.grumpysperformance.com/index.php?threads/odd-starter-related-problem.5926/#post-18562

http://garage.grumpysperformance.co...lem-getting-the-engine-started.63/#post-31920

http://garage.grumpysperformance.co...rters-and-started-related-info.458/#post-1545

http://garage.grumpysperformance.co...lem-getting-the-engine-started.63/#post-31920

http://garage.grumpysperformance.com/index.php?threads/problem-with-starter.1646/#post-26319

http://garage.grumpysperformance.com/index.php?threads/is-my-alternator-shot.7808/#post-26803

http://garage.grumpysperformance.co...k-clunk-clunk-start-problem.11422/#post-54990

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

http://garage.grumpysperformance.co...wrong-after-alternator-swap.13580/#post-70168
 
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