kwhizz

While driving the Impala on a road trip (2006 GTO LS2 drivetrain)......I noticed that after a couple days of driving, the Voltmeter would fluctuate between 12 and 14 volts..........it would stay at 12 Volts for quite a while then move up to 14...........if I stopped for a while then it would stay at 14 Volts for a while before dropping again.......What's going on here ????

67Skylark

My did the same thing just before the alternator died. I'd just replace it.

kwhizz

Thanks............My thoughts exactly........Just was wondering if the ECM had anything to do with it..........


Ken

Project GatTagO

iTrader: (7)

If it was at 12 volts, that means it wasn't charging at all. I'd have it tested and probably needs a new one.

Also, do you have the S terminal on the alternator wired?

Andrew

kwhizz

Worked perfectly for 5 years...........But......That was then and this is now.......Andrew.....Stock Harness modified by Speartech 5 years ago.........Ordered a New Alternator............

Thanks

Ken

bigpat1802

I had that happen...took the alt to a shop and something that was supposed to be soldered, wasn't.

kwhizz

This car stuff is hard........LOL.....Bought a new Alternator.......while taking the old one off, and after removing the nut from the battery charge wire , I noticed that the inner nut that keeps the stud compressed and tightened against the plastic case was about three threads from being tightened as it should be........so......It's possible that everything was tightened between the nuts.........the stud was allowed to not be tightened as designed...............Put the new alternator on......started it up and Bingo .......14 Volts with no fluctuations..........Like I said, This car stuff is hard........LOL

kwhizz

After thinking about what I posted ................Disregard.......Doesn't make any sense.........Just looking for any reason.....LOL

kwhizz

Took the car out yesterday with the new GM alternator (old one was a new Chinese unit) and put some miles on it......Voltmeter stayed right at 14 Volts all day........never fluctuated once...........Not gonna try and figure it out ......