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Discussion Starter · #1 ·
Hey everyone. So I just recently replaced my battery and alternator in my 02 TB. I now have some dome light flickering. Meter shows a .2-.3 volt fluctuation with motor running in idle when flickering is occurring. Any ideas? Alternator is a remanufactured AC Delco and battery is brand new Costco interstate battery
 

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Why did you replace the alternator and battery?

What changed - if anything?

Run a Digital Volt Meter on the stud that comes out of the battery to test the voltage.

First, start the engine and check for the DC voltage.
Then test for AC voltage on that same stud.

Report back. Pay attention to the decimal place holders.
 

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Discussion Starter · #3 ·
Thanks Ravalli. The battery was over 5 years old. Alternator was no longer charging it so i replaced both at the same time to ensure that alternator was charging a good battery. I will do voltage test and get back
 

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Discussion Starter · #4 ·
Ok so the weirdest thing happened this morning....I drove my vehicle in to work and when I turned off my vehicle and then turned it back on again the voltage shot up to 16-17 volts! Then it would drop to 10 volts and then back up again. I turned off vehicle and restarted it and it was stabilized ...still have dome light flickering. Weird
 

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Are there any other symptoms we should know about?

Awaiting voltage results. Be sure to test both AC & DC voltages and try to do so at idle and then at maybe 1200 RPM to get the alternator off the 400Hz induced field stimulation zone at idle.

You also might want to test with as many accessories ON as you have, to push the alternator harder ... kinda like running a treadmill during a cardiac test.

Please be sure to take those readings directly from the B+ post on the back of the alternator.

The closer to the battery you test, with the battery acting as a giant capacitor, the less accurate the results will be.



.
 

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Ok so I replaced the remanufactured alternator with a new one and it solved the problem. Looks like the voltage regulator inside the alternator was bad.
A defective diode pack or diode trio inside the alternator - but voltage regulation is done by the computer.

Do you mean "NEW" in the classical sense or just "New to you"?
 

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Ahhhhhhhh.... best kind. There was a company called --- uhmmmmm .... let me try to remember ---- APICO* --- yup - that's it.
* Note - not AAPICO, which still exists and MAY be a new iteration of the old APICO --- but I think not.​

Anyway --- they sold brand new and it was 110% brand new - including the boxes they came in. I loved their stuff so I guess it's not too far out the think another company did that too --- make and sell new alternators and such.

I had a few failures - not that you for sure will - but just be aware that it happens on new electronics. Good on ya for figgerin' it out.
 
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