Jumpy Battery Voltage

[Nash]

My car has been having some jumpy battery voltage problems. It likes to jump between about 13.5-14.5, according to my logger. My lights, headlights and gauge lights flicker while I am driving or while I'm stopped. I had the alternator off and tested and it tested good, 14 volts. Anyone have any ideas what could be causing this? Could it still be the alternator even though it tested good? I check all of the connections and they seemed good. The car is a 90 TSi AWD.

[joem]

Short in the battery maybe.
joe

[john]

The battery should be out of the question if the car is running. It is then running off the alternator (if it is good) or the battery if it is not. I was having similar problems on and off in my car. I haven't yet figured it out. I have a new alternator and a new battery. I am going to just start checking grounds.

[Goat Blower]

Voltage regulator. It's located inside of the alternator, I'd have some auto parts store check the alternator on their load tester.

[Super Bleeder!!]

^^^ i was gonna say that, damn you hill!

[npaulseth]

Originally posted by gixxer@Oct 25 2004, 01:25 PM
^^^ i was gonna say that, damn you hill!
dido. I would bet money that's the problem.

[Nash]

Originally posted by Goat Blower@Oct 25 2004, 12:15 PM
Voltage regulator. It's located inside of the alternator, I'd have some auto parts store check the alternator on their load tester.
I did have it tested, tested at 14 volts all three times.

[1Fst14B]

try another "test" battery.

ive seen many times where the battery effects alternator output.

and no, when the car is running, the battery is not "out of the picture"

other than that, alternator...but if its already tested good....

[Pushit2.0]

quick check on the battery/alternator
-if the car starts fine but dies when the batter is disconnected the alternator is shot

-if you jump start the car and runs fine untill you shut the car off again or it stays running when you unhook the battery, the battery is bad.

What is the car idleing at? I know when my car idle surges it has flickering lights and what not.

~John

[x1genx]

Yea, I have had the same problem now for the last 3 months, and four alternators later and 2 batteries it was still acting up, I finally said fuck it with the shell altogether now that I have a diffrent shell but i still wish i knew what it was. I started checking grounds but it would still fry my alt after 500 miles or so of driving. I would throw a used alt in and then test it out with a new battery and it would run solid but man give it like a day and the voltage would start jumpin like whoa and then settle...and then settle lower....and then it would just stop recharging the battery altogether. I wish I had the answer.