electrical woes/ alt & bat good
#1
01-10-2007, 08:05 PM
electrical woes/ alt & bat good
I've got a 96 a4 quattro 2.8 and the charging system is killing me. i just put a rebuilt alternator back in that i had tested at autoblown. they said it was good, tested the battery same deal, passed. car runs fine but if i turn on lights, heat, wipers etc... voltage drops. tested with multimeter gauge is mint, checked wiring from bat to alt, mint. i can't figure it out PLEASE HELP!!!
#2
01-10-2007, 09:16 PM
RE: electrical woes/ alt & bat good
Was the alt. test with a load on it? If the person doing it didn't do a load test while testing the alt. it could still be bad. Was any work done on the car recently? It could be a ground issue, bad ground strap or someone forgot to hook back up a ground strapp during a service.
#4
01-10-2007, 10:29 PM
RE: electrical woes/ alt & bat good
i dont know if they load tested it. brought it to autozone where the kid put it in the box and it passed. frickin kid was hugging the rig so i couldn't see what the screen said. it shure seems like a crap alternator to me. when you put any real load on the system it gradually stops charging coresponding to how much stuff i got on. for instance 13 parking lights, 12.5 and dropping with the headlights. i just cleaned the battery ground and the body to engine ground today.
#5
01-10-2007, 10:48 PM
RE: electrical woes/ alt & bat good
Sounds like you have a bad "exciter diode" or a bad voltage regulator. Both should be on the alt.
With the car on, what is the voltage at the battery? It should be 14.4v.
With the car on, what is the voltage at the battery? It should be 14.4v.
#6
01-10-2007, 11:12 PM
RE: electrical woes/ alt & bat good
voltage is at 14.4 after alittle reving and stays there as long as i don't turn anything on(if just the stereo is on its ok). i haven't heard of an exciter diode, whats it do? this is the second rebuilt alt, the first rebuilt one the voltage reg went after bout 6 months(volts would race with the engine to 16 or so)i put a new one on and the alt wouldn't charge at all. so i got a rebuilt one from autozone "gauranteed for life"... to be a piece of $#!t. so as soon as i put it in i have had the curent problems. so today i pulled it out went back down there and it passed the bench test. so what is an exciter diode?
#7
01-10-2007, 11:45 PM
RE: electrical woes/ alt & bat good
It helps control power output duringa load, such as when the headlights are on. I'm not sure if a bench test can test an alt. under load.
#8
01-10-2007, 11:47 PM
RE: electrical woes/ alt & bat good
ORIGINAL: direwolf57
voltage is at 14.4 after alittle reving and stays there as long as i don't turn anything on(if just the stereo is on its ok). i haven't heard of an exciter diode, whats it do? this is the second rebuilt alt, the first rebuilt one the voltage reg went after bout 6 months(volts would race with the engine to 16 or so) i put a new one on and the alt wouldn't charge at all. so i got a rebuilt one from autozone "gauranteed for life"... to be a piece of $#!t. so as soon as i put it in i have had the curent problems. so today i pulled it out went back down there and it passed the bench test. so what is an exciter diode?
voltage is at 14.4 after alittle reving and stays there as long as i don't turn anything on(if just the stereo is on its ok). i haven't heard of an exciter diode, whats it do? this is the second rebuilt alt, the first rebuilt one the voltage reg went after bout 6 months(volts would race with the engine to 16 or so) i put a new one on and the alt wouldn't charge at all. so i got a rebuilt one from autozone "gauranteed for life"... to be a piece of $#!t. so as soon as i put it in i have had the curent problems. so today i pulled it out went back down there and it passed the bench test. so what is an exciter diode?
I would get you money back, and pick up an AUDI alt. Yes it will cost more, but I'm sure it will work.
I WOULD NEVER buy any electrical stuff from Autozone.
#10
01-11-2007, 03:38 PM
RE: electrical woes/ alt & bat good
alternator is back in and im bringing it down to autozone to have the charging system tested.