Even more Alternator woes
 

This is worse than a soap opera!

I started a thread a little while ago about a friends A8 and it's alternator problem, well it's got a whole lot worse. A second hand part was sourced and fitted by a local garage, the car started, after a few seconds the battery light glowed brightly then there was a slight grinding noise and a plume of smoke (from within the alternator it seems) one more knackered alternator for the scrap pile!

I was off visiting family at the time and returned to find irate messages on the answerphone. About second hand parts being usless blah, blah, blah:(

So on Monday I recovered the last fitted alternator from the upset Audi owner, just to try to see what was causing all these problems. On opening it up the slip ring was found to be badly worn and the regulator appeared to have arced, it's carbon bushes were just about worn out and very sticky in their mountings. So, I called in a few favours and raided another friends spare parts boxes, result about an hour later one semi reconned alternator. I replaced the slip ring with a brand new unit, likewise the rear bearing was also renewed. The regulator was replaced with a known to be good second hand unit, with almost unworn carbon brushes. Feeling somewhat pleased with myself I called to see the A8 owner yesterday. 'Oh you shouldn't have bothered mate' was the reply I got on showing him the results of my efforts. 'The garage are fitting a brand new alternator today' I nearly threw the damn thing at him :rolleyes:

Got a 'phone call this morning, it seems that the garage fitted the new alternator, only for it to fry itself within five minutes. They've checked all wires and the noted corrosion spot of what I call the junction box in the front wheel arch area. Nothing of concern was found. Another new alternator is being fitted today I wonder if this one will solve the problem?

One very odd thing that seems to happen just before the alternator gives out it's smoke signal and tenders it's resignation. The sunroof opens itself without anyone touching the control switch:Confused: I think the car is hexed. Anyway I've got myself a nice little 150 Amp alternator that should be good to go sitting in the garage waiting for the opportunity to expire in a cloud of smoke:ROFL:

Has anyone else ever had such aggro with A8 alternators? Or are we trendsetters? :ROFL:

I've had sunroof and passenger window open independently of any controls but can't for the life of me remember if that was before or after i re-done the juction box area, it is at that box that the alternator and starter get their power cables from / to isn't it?

I'm no good with the dark arts or electric's so i'll just wind my neck in.

One simple question: Genuine Audi alternator?

If it's got a bad earth point at the front, then you get all manner of electrical shenanigans.. Conan ended up having to be taken back on a low loader as a result once if I remember rightly..

I'd suggest they get that cleaned up pretty sharpish.

I've just got off the 'phone with an update. Good news at last.

So, the garage moaned like hell to their trade supplier, who in turn must have made a few calls to Bosch. The Audi's owner in the meantime threatened to sue anyone who was found within a 50 yard radius of the car. End result, one fully trained Bosch engineer turned up at garage at 08.00 this morning and refused to let any of the garage staff touch the Audi. This gentleman then set about running all kinds of tests on the cars electrics, the cars owner was very impressed with this approach. Sure enough a corroded earth wire was found on the front chassis to subframe mounting point? I hope to get more details later, could be very useful info for all of us. This wire was replaced and the new alternator (it's fourth) fitted. The car then sprang into life and was test run for the better part of an hour. whilst further tests were conducted. It was then road tested for fifty miles. and it didn't expire in a cloud of acrid smoke.

The engineer also noted that the wiper motor was drawing more current than he would expect it to and suggested that the linkage may be tight. He also detected that a rear door micro switch (located where?) was creating a parasitic battery drain also the sunroof relay was found to have corroded terminals.

Everyones now happy, the garage feel they fought their corner pretty well and the A8's owner now has a fully operational car albeit with a few minor fixes required. The Bosch engineer was impressed with the 8 stating that he prefered the D2 to the later models. All I've got to do now is pay for the 150 Amp alternator that's sitting in my garage. What's a knackered alternator worth these days? The parts I fitted to it were sourced FOC.

Thanks to everybody who took the time to contribute to my threads, I am still keen to learn of the location of this troublesome earth wire.

If you look at the chassis leg on the inside of the front wheel, that's usually the culprit

Thanks for that, I'll be checking my pair of D2's out as soon as it stops raining. I assume it's located on the O/S (RHD), same side as the 'junction box for the positive leads and the alternator?