VR / Alternator Problem

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May 18, 2007 | 09:59 AM

BrettG

Thread Starter

Burning Brakes

Joined: Sep 2005

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From: Greenwich CT

VR / Alternator Problem

Purchased a restored alternator over the winter & installed on car recently. Since getting the car running (last week), I've noticed that the voltage regulator is warm while the car is off - I've since changed it to the VR unit.

Had the carb. tuned / timing checked yesterday & noticed that the battery(new) wasn't holding a charge.

Hooked up my volt / ohm meter to the battery while running and confirm its not receiving a charge.

Can anyone suggest a testing sequence to confirm the fault?

May 18, 2007 | 11:19 AM

Dicecal

Melting Slicks

Joined: Aug 2001

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From: Phoenix AZ

Quote:

Originally Posted by BrettG

If you have the service manual, there is a series of tests they walk you through to troubleshoot the problem. If you have confirmed the alternator is good, then the voltage regulator may not be putting out enough volts to charge the battery. That would surprise me however, if you have the wells VR715 in there. If you have TI ignition system, the TI voltage regulator is adjustable (so is the old style non-TI VR), you may need to increase the voltage output of the regulator. I'd suggest getting a copy of the service manual to go thru that procedure.

Last edited by Dicecal; May 18, 2007 at 11:25 AM.

May 18, 2007 | 01:24 PM

JohnZ

Team Owner

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From: Washington Michigan

Is the base of the regulator grounded? If the ground wire isn't attached, the regulator won't work.

May 18, 2007 | 01:34 PM

BrettG

Thread Starter

Burning Brakes

Joined: Sep 2005

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From: Greenwich CT

Quote:

Originally Posted by JohnZ

Is the base of the regulator grounded? If the ground wire isn't attached, the regulator won't work.

As I recall, there are two ground wires attached to the base - one for the headlight wiring & one from the engine wire harness - there is also a capacitor mounted at this location.(which plugs into a side terminal on the rear side of the VR.)

Am I missing something? Should I run a separate ground direct to battery & verify charge condition?

May 18, 2007 | 10:16 PM

buns

Safety Car

Joined: Feb 2006

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Quote:

Originally Posted by BrettG

Hooked up my volt / ohm meter to the battery while running and confirm its not receiving a charge.

Can anyone suggest a testing sequence to confirm the fault?

Here is the test that will bypass the voltage regulator.

p.s. the "Delcotron" is the alternator.

May 19, 2007 | 11:01 AM

BrettG

Thread Starter

Burning Brakes

Joined: Sep 2005

Posts: 1,014

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From: Greenwich CT

Buns,

Thanks for the testing procedure, I'll hopefully have time this weekend to try it.

UPDATE:
Purchased & installed my second Wells VR715 and reinstalled the alternator which came with the car - still not charging!!!
Not looking forward to bringing the car to a shop!

May 19, 2007 | 08:11 PM

plaidside

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BrettG,
I just posted to my website a detailed alternator/regulator test procedure.
I had my wife proof read it and she says she understands it! Scary.
Let me know what you think.

http://temp.corvetteforum.net/classi..._Testing.shtml

Last edited by plaidside; May 19, 2007 at 08:14 PM. Reason: Forgot to enter link

May 20, 2007 | 11:50 AM

BrettG

Thread Starter

Burning Brakes

Joined: Sep 2005

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From: Greenwich CT

Quote:

Originally Posted by plaidside

Joe,

Thanks for the detailed explaination, I'll spend some time running through your testing procedure later today.
I happened to read something about the VR being warm to the touch, which will cause the battery to drain - this is exactly what was happening to me!