bounce a few ideas this way please!

grumpyvette

grumpyvette

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I recently helped a guy replace an intake on his 1987 corvette and due to several issues the car sat un, driven for about 3-4 months, now when he starts the car the alternator smokes, which it never did previously and smells like its burning internally,obviously I could replace the alternator,but want to locate the cause of the failure, the alternator was never disconnected , the car runs, but Im very concerned because of the smoking alternator, any ideas are welcome.
yes I can do an alternator test, but regardless of the result a previously functioning alternator just doesn,t normally fail from just sitting so while it may be a coincidence Im looking for potential reasons it failed.
if it was my car ID just install a 200 amp alternator (like Ive done)
http://www.dbelectrical.com/p-9237-alte ... -1986.aspx
as the current alternator he has is original and at least 24 years old., Im not so concerned with correcting the problem as finding the cause... yes it just might be a coincidence that the old alternator picked that time to fail, but I always find that just simply replacing parts without finding out what caused the failure is seldom the best route to take in repairs
keep in mind knowing exactly how things are supposed to be working and researching exactly whats actually occurring in the real world are not necessarily similar pursuits, nor is logic always going to lead you to the correct answer but in most cases, dragging out a shop manual and doing a few logical tests, well, thats the best route to follow.

http://www.sengpielaudio.com/calculator-ohmslaw.htm

http://www.stealth316.com/2-wire-resistance.htm
 

Can we assume you started the car right after replacing the intake and nothing was wrong at that time???

 
Indycars said:

Can we assume you started the car right after replacing the intake and nothing was wrong at that time???
Click to expand...
. no the car sat for 3-4 months, un-started and un running because the car required other work that was un-related and the battery was dead, and the new battery was not hooked up till now.

HERES TWO OTHER REPLYS

He has a Delcotron CS-130 alternator on his 87 Vette same as my 87 vert Grumpy.
Sure you know this already.

You did not say what kind of smoke, electrical enamal copper wire insulation burning or steel on steel with grease burning.

One weak spot with the CS-130 alternators are the rear rotor ball bearing in the end frame.
I have had 2 of those bearings fail on my 87 in the last 5 years.
One was on a brand new Power master XS 140 amp output alternator.
Repaired & replaced the bearing myself.

The very best Delcotron alternator bearings made were made by New Departure.
They are long gone & defunct.
may be able to track down NOS.

Every single reman alternator out there uses ball bearings in china.
All ball bearings are graded.
1 through 5.
New departure was #1. The best.
What we get now is #5 china. Cheap as they can make it.

Before total ball bearing failure,
the electromagnetic rotating field or alternator rotor is allowed to move around 1/8" inch or more from true designed centerline.
Every now & then the rotor makes contact with fixed field windings- stator assembly.
So great friction of steel on steel is present, sparks, and smoke.
Eventual the stator assembly fails from excess heat & severe vibration.
Short in the delta or "Y" windings.

All high production remaned alternators use the cheapest full wave rectifier bridge available.
40 amp diodes that also have excess reverse bias voltage leakage at rated peak working voltage.
China hardware here too.

Best ball bearings currently available for the CS-130 alternator are made my Natchi. made in Japan.
What I am using.
Best CS-130 alternator rectifier bridge are made by TRANSPO. Company Based in Florida.
90 amp( per diode) full wave rectifier bridge I am using.

Power master XS alternator adjustable voltage regulator & supplied rectifier bridge failed 3 years later on me.

So all internal guts are now GM Delcotron.
Natchi bearings.
Transpo solid state Electronics.
I put together myself.
Works better than any aftermarket alternator & 100 % reliable now.

Brian

Most never notice the rear CS 130 ball bearing failing.
Only tell tale sign is a funny chirp or squeak on unpredictable occurrence.
Like a serpentine belt squeak then quits.
Or like a small mouse squeaking in the garage.

Many complaints of poor charging output from CS 130 alternators are due to the substandard parts installed upon rebuild.
Like the full wave rectifier bridge.
Thermal runaway happens under load & heat soak present.
Especially prolonged idle in traffic on a 90 to 100 F day.
Poor PN junction present in the diodes internal.

Can be checked on a transistor - diode curve tracer like a vintage Sony- Techtronics unit.
Graph it.
Poor electrical connections, degraded weathered charging output terminals, field connection wiring & plug issues also another large culprit in alternator charging system problems.

One of the best ways to test an alternator is to use a SUN Vat 40 carbon load pile.
Rev engine to 2,000 RPM's & hold steady.

Alternator pulley step up ratio is 3:1.
2,000 crank RPM's & alternator rotor is turning 6,000 RPM's.
Where most alternators are designed to output maximum current or amps.

Then adjust the carbon pile connected in parellel across the battery to 100 amps.
About what most C4 alternators are designed to output max.

Watch the voltage for 10 to 15 seconds.
Alternator voltage output must not drop below 12.6 vdc.

Don't exceed rated amperage rating of alternator tested & no longer than 15 seconds.
This test works the entire alternator real hard to 100 + % duty cycle.
Tremendous EMF heat buildup is also a byproduct.

But the test is 100 % foolproof as installed on the car or your Corvette.

I have been testing in this manner for over 20 years.

How it was done in the 1960's & 1970's by veteran mechanics & how I was taught.

Most don't understand.
But you are a mechanical & electrical engineer.
Sharing knowledge & experience with you.

BR

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What kind of smell the smoke has? maby its some oil or debrits. If it is smelling burned electronic its not good.
Otherwise maby its the bearing that are seizing? its all i can think of.
 
IM leaning towards either worn brushes or defective bearings in the alternator, ILL post what I find
smoke smells like electrical wire insulation to me but Im not positive its the source, but one other factor I just noticed is the main charge wire that hooks where ther red arrow points, going back to the battery looks like its getting hot !
wolthuis.aspxa.jpg
 
I really appreciate the input, gentlemen, as it helps prevent me skipping over simple things I might otherwise forget , or failing to address issues, or failing to answer questions as this is supposed to be a learning experience, and helpful in increasing all our skill levels, I might otherwise take for granted everyone should know, what both of us know, which of course is a false assumption and Im sure a great many other people do appreciate your input on this also.
but I want to point out one factor, I purposely post questions most of the time to get people to think things thru, in many cases I strongly suspect or have already found the answer, in a few Im truly perplexed , and looking for an answer I can,t seem to find, but want to get people thinking, involved and questioning what needs to be tested.
In this case I found the answer, after a bit of testing and only after posting the question thru a couple minutes testing, with a multi meter, but I want to see how long it takes to get the correct route to finding the answer posted.
I think this thread could prove to be very informative, so Im going to continue looking a bit clueless until I get the correct answer and how it was found posted..
lets see how long this takes?
If you read this and start thinking , whats this jerk, thinking, I think you took that post wrong, and I truely apologize, if in any way you thought I was rebuking your input, or ideas, that the last possible thing I intended, as you gentlemen reading this probably know as much or more than I do, remember Im an old geezer and was forced into retirement 12 years ago so I tend to forget a few things, I look forward to your posts and always find I learn things reading thru them, the point I hoped to make was only that Id let this drag on until I get lots of ideas posted, hopefully valid ideas and a discussion of how and why you test things, and a logical path, or course of testing and what to look for in each test, to locate the problem discussed
 

What voltage is the alternator putting out from the battery terminal to ground?

Maybe the voltage regulator is faulty and causing the voltage to be too high and overloading the alternator.

 
One thing I've found over the years is that coincidence will make you crazy with cars. You work in a certain area or on a certain part and when your done or shortly after, some part you touched or related to what you did fails or acts up. Immediately we assume to be something we did. Often something else has failed at near the time we worked on it. I remember totally rebuilding/replacing the entire ignition system onan '89 Formula 350, when done, no start! I rechecked every piece I'd worked on and everything checked out. When I finally decided it had to be something else, the MAP sensor was bad and the injectors wouldn't fire, replaced it and it fired right up.
I know, not related to the alternator smoking but sometimes where there's smoke, the fire is somewhere else. :mrgreen:
 
because some of you guys don,t seem to want to offer valid suggestions heres the test details I found

with the car sitting and ignition switch off
the battery voltage reads 12.5 volts at both the battery terminals and from frame ground to the alternator out put stud

resistance in ohms from the alternator stud to the positive battery terminal reads 4.5 ohms
measure from the battery negative to the outer alternator case (14 ohms) (both normal)


with the car sitting and idling at 870 rpm ignition switch on
voltage at the battery jumps to 15.8 volts with the alternator stud lead connected, disconnecting the power to battery lead and connecting the meter between the alternator output stud and engine frame ground,allows the alternator output to jump to 22.2 volts, so obviously the alternators internal voltage regulators shot and needs to be replaced or the alternator needs to be replaced, so its just a coincidence that the alternator failed after sitting for a few months, and had zero to do with previous work.


READ THRU THESE LINKS
http://www.ehow.com/video_4936008_insta ... nator.html

http://www.bernardembden.com/xjs/altmove/index.htm

http://www.youtube.com/watch?v=Cip-dmaT ... re=related
http://www.harborfreight.com/alternator ... 69018.html

http://www.harborfreight.com/500-amp-ca ... 91129.html

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

viewtopic.php?f=36&t=3222&p=8575&hilit=test+alternator#p8575

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

http://oljeep.com/gw/alt/edge_Alternato ... #Section_1
 
The voltage regulator in most newer GM cars is in the alternator. The simplest way to replace the voltage regulator is to install a rebuilt alternator, it is also the most expensive. you can more than likely find a used alternator at a salvage yard for under $30 or rebuild your current alternator if you can find components
To replace the voltage regulator in your alternator:
1. Remove the ground cable from the battery.
2. Unplug the wires to the alternator.
3. Remove the alternator.
5. This is a good time to check the alternator bearings. Spin the pulley and if the alternator is noisy or stops almost immediately you probably need new bearings.
6. Take out the bolts that hold the alternator halves together and take the halves apart. Mark the halves so you know where to put them back.
7. This is a good time to check the brushes. If they are excessively worn it is a convenient time to replace them. Look at the commutator, it should be smooth.
Take a look at the field coils to see if they are burned. or have any broken wires.
7. Take out the old voltage regulator and install the new one.
8. There are two tiny holes in the brush holder. Insert a wire in the holes to hold the brushes back so that you can get them over the commutator. The wires should extend to the outside of the housing so that you can pull them out when the alternator is put back together.
9. Put the two halves back together aligning the marks so you have it in the right orientation. Put the bolts back in and tighten them.
10. Pull out the wires that held the brushes away from the commutator.
11. Put the alternator back in place, install the wires and the belt. Tighten the drive belt..
12. Put the ground back on the battery.
13. Start the engine and check to see if the alternator is now charging the battery.

http://oljeep.com/gw/alt/edge_Alternato ... #Section_1

http://carrepairguide.org/Troubleshooti ... nator.html

http://store.alternatorparts.com/cs130d ... lator.aspx

http://alternatorparts.com/ad_alternator_order_page.htm
 
so obviously the alternators internal voltage regulators shot and needs to be replaced or the alternator needs to be replaced, so its just a coincidence that the alternator failed after sitting for a few months, and had zero to do with previous work.
Click to expand...

My point exactly! I'm not an electronics whiz so any specific suggestion on my part would have been a guess. But coincidence has driven us all crazy and is often where the trouble lies.
 
Indycars said:

What voltage is the alternator putting out from the battery terminal to ground?

Maybe the voltage regulator is faulty and causing the voltage to be too high and overloading the alternator.
Click to expand...
You never said what I won for being the closest ???

Is it a new car or a free lifetime subscription to the forum ??? :p

 
Indycars said:
Indycars said:

What voltage is the alternator putting out from the battery terminal to ground?

Maybe the voltage regulator is faulty and causing the voltage to be too high and overloading the alternator.
Click to expand...
You never said what I won for being the closest ???

Is it a new car or a free lifetime subscription to the forum ??? :p
Click to expand...

in situations like that, where I knew the answer first, in any discussion,I have with the wife, I usually grin and ask the wife if that entitles me to more SEX since Im obviously correct, she usually responds with something like, WHY ITS NOT YOUR BIRTHDAY! GO MOW THE LAWN!
 
87vette81big posted this

"The high limit Voltage Setpoint of the CS 130 alternator is out of Range, Way off.
Voltage regulator Defective as you said Grumpy.

15.1 vdc should be maximum regulated output voltage @ 60 F & lower.

There is a thermistor with a negative temperature coefficient inside of the Solid state voltage regulator.
As outside temps drop, charging voltage is slightly increased.
As outside temps rise, voltage output drops.
To prevent acid boiling internal of the vehicles lead acid storage battery on 90 F to 100 + F days driving.

What bothers me yet is your measured resistance the alternator charging output wire back to the battery.
And the negative battery cable connection tested to the alternator case body.

Readings are slightly high to my liking.
Thinking corroded / or loose connections are present.
Or defective terminal end crimps.
Or battery sulpheric acid has leached, wicked up the copper wire strands, and degraded wiring internal of entire cable length.
Check for insulation bubbling on the outside Vinyl jacket.
Means there is severe corrosion present underneath.

I would like to see around 1.0 ohm or less myself on your tested charging output wire & alternator negative ground system.
C4's like my 87 & your project have very short alternator wiring circuits back the vehicle battery.
4.0 ohms too high I believe.

Voltage drop tests my favorite way to check charging & starting system wiring.
Very accurate test.
You can also calculate amps though that circuit using Ohms Law. E divided R.
Or Watts too. E X I & I squared X R.

Brian "
 
72novaproject posted this info

"I would say both of these are positive test results. With the lead connected, the voltage regulator is responding appropriately to an under charged battery. With the lead disconnected, the voltage regulator is sensing zero voltage and goes full field in an attempt to bring the system to 14.2 volts.

A more accurate test would be to use an ammeter with an inductive clamp and a carbon pile on the battery to load the system and observe the reaction of the voltage regulator.

As far as the smoke goes there is only one thing that can cause it, high resistance in an electrical connection or component that creates heat and therefore smoke. After the charging system test a visual inspection of the internal components of the alternator would be the appropriate next step.

Steve"
 
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