Further Diagnosis - Charging System - The 1947 - Present Chevrolet & GMC Truck Message Board Network

*Zilverado* · 01-10-2003, 10:27 AM

So here's the deal:

After driving a little (engine warmed up), come to a stop light, stay in drive, the following happens:

Charging system volt meter drops from 14 to approx. 12.5 V.
Engine rpm drop slightly, and idle becomes slightly rough.
Dash lights dim, fan slows, etc.

So the question is, does the drop in the charging cause the engine to slow or is the engine idle effecting the charging? You know - the chicken or the egg thing???

**swervin ervin** · 01-10-2003, 11:17 AM

If I were guessing, I'd say the alternator may be on it's way out. Of course I would check the belt tension and all connections to make sure everything is up to snuff before replacing anything. Clean the battery cable ends too.

From my experience, this is the first sign of a alternator biting the dust. It only gets worse if it is.

BigRed · 01-10-2003, 11:21 AM

I agree with Mike, that definitely sounds like a failing alternator! Hey, but that's good new. That's an easy fix!

*Zilverado* · 01-10-2003, 02:16 PM

As always, thanks for all the help and advice.

Made a few calls this morning and have decided to rebuild the old alternator instead of replace it. New $214, rebuild $125 (Canadian dollars). According to the rebuilder, $125 covers replacement of the internal regulator and possibly the rectifier as well. If these are not needed, the price drops considerably - just bearings, brushes, reinsulating the stater and balancing the rotor. And with a 2 year warranty, it's worth it.

Oh, and just in case you thought this was alot of effort for a '86 Chevy, it's actually for our Pathfinder.

Thanks again.

BigRed · 01-10-2003, 02:21 PM

Quote:

Originally posted by Zilverado
As always, thanks for all the help and advice.

Oh, and just in case you thought this was alot of effort for a '86 Chevy, it's actually for our Pathfinder.

Thanks again.

Huh, I was wondering why the alternator was going to be so expensive!!

*Zilverado* · 01-10-2003, 02:51 PM

Quote:

Originally posted by Riptide's 78p/u
Best of luck to ya buddy

Hey thanks Rip,

Now if only this could have happened 2 days ago when it was +8C in the 'Peg, eh. Oh well, better now than in the middle of a long road trip.

......and BIGRED

I thought I better clarify the make and model of the vehicle, lest people thought I was completely devoid of smarts and letting someone rip me off real good.

Anyway, thanks again.

01-10-2003, 10:27 AM	#1
Zilverado Account Suspended Join Date: Nov 2002 Location: Winnipeg, Manitoba, Canada Posts: 798	Further Diagnosis - Charging System So here's the deal: After driving a little (engine warmed up), come to a stop light, stay in drive, the following happens: Charging system volt meter drops from 14 to approx. 12.5 V. Engine rpm drop slightly, and idle becomes slightly rough. Dash lights dim, fan slows, etc. So the question is, does the drop in the charging cause the engine to slow or is the engine idle effecting the charging? You know - the chicken or the egg thing???

01-10-2003, 11:17 AM	#2
swervin ervin You get what you pay for Join Date: Dec 1999 Location: Cherryville, NC Posts: 4,798	If I were guessing, I'd say the alternator may be on it's way out. Of course I would check the belt tension and all connections to make sure everything is up to snuff before replacing anything. Clean the battery cable ends too. From my experience, this is the first sign of a alternator biting the dust. It only gets worse if it is. __________________ Mike 1985 Chevy C-10

01-10-2003, 11:21 AM	#3
BigRed Registered User Join Date: Jun 2002 Location: DFW, TX Posts: 1,680	I agree with Mike, that definitely sounds like a failing alternator! Hey, but that's good new. That's an easy fix! __________________ Scott Shelbourne

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01-10-2003, 02:16 PM	#4
Zilverado Account Suspended Join Date: Nov 2002 Location: Winnipeg, Manitoba, Canada Posts: 798	As always, thanks for all the help and advice. Made a few calls this morning and have decided to rebuild the old alternator instead of replace it. New $214, rebuild $125 (Canadian dollars). According to the rebuilder, $125 covers replacement of the internal regulator and possibly the rectifier as well. If these are not needed, the price drops considerably - just bearings, brushes, reinsulating the stater and balancing the rotor. And with a 2 year warranty, it's worth it. Oh, and just in case you thought this was alot of effort for a '86 Chevy, it's actually for our Pathfinder. Thanks again.



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