Fw: Alternator dont Charge - red warning lights are on - FIXED

[Kneale Brownson]

I've had two Audi alternators fail when the windings shorted because the
cases rusted internally enough to form a bridge to the windings and cause
the shorts.  The service shop showed me the windings.  Looked like a little
volcano erupted with the wires from the winding bursting outward. I
couldn't believe how much rust was inside those cases.  I assume this is a
pretty common failure considering that Audi tucks the alternators down low
where wheelsplash gets to them so easily.



At 12:26 AM 11/24/2006 -0500, SJ wrote:
>I replaced the alternator with a 100amp Bosch rebuilt unit. Price was $175
>plus tax, and the old alternator core.
>
>Before buying a replacement, I had the old alternator tested at two places.
>The auto zone guy didnt know what the hell he was doing. I had to hook up
>the cable adapters for him. Alternator read "dead as doorknob".
>I also tested the old alternator at a auto electrical shop near me. It also
>tested dead. The owner said it was most likely open stator winding(s).
>
>I had tested the rotor winding by measuring the current going to them with
>ignition key on. Current was 370 ma. Spec is about 175 ma. I tested the
>rotor winding by measuring at the slip rings. I got a couple of ohms on the
>rotor. I measured also from slip rings to ground . .. no shorts. I concluded
>the rotor was probably ok, and the problem was with the stator.
>
>I tried taking the alternator apart with no luck.
>I removed the pulley.
>Two bolt heads holding the cases together stripped out. I had to drill the
>bolt heads off.
>I couldnt pry the cases apart. The case material was chipping off and they
>still would not seperate. I got some movement of the case halves but no
>seperation. I guess 18 years of corrosion welded the case together.
>I didnt want to damage the alternator anymore, fearing they wouldnt take it
>as a good core. So, I wussed out and bought a rebuilt alternator.
>
>Sorry guys . . .I failed . . . . .. I feel soooo bad about this . ..