koolhand

89 200TQ, Started this morning, battery light was dimly lit, charge was just less than 12V, tapped accelerator and Voltage gauge jumped to just under 14V. Dropped the wife off (touting the advantages of driving her to work, traction benefits from Quattro with impending snowstorm...)
voltage again dropped off to less than 12V, did so for most of the trip to local battery/alternator shop who gives free diagnosis. About a block from the shop, charge jumped back to almost 14V...problem not seen since.

Thinking I might need new alternator, saw the following quoted from SJM site:
"BEFORE installing this alternator, refer to Application Notice #B-85 in the Bosch reman catalog regarding charging problems during wet weather"
Yeah, it was raining pretty hard last night and this morning. Could this effect charge?

audi-bahston

Try tightening it up and see if the voltage stays some what contsant. I've been chasing some alternator demons myself lately. I've got a brand new remanned unit sitting in the bedroom waiting to go in for next to nothing on Ebay. It was actually less money than what I paid for the ****ty used one I got from ___________! I'm hoping to not worry about the damn charging system for a while.

BTW are you getting any weird lights when you start the car? Battery, Brake and ABS light when you start her up? Staggered at the bottom of the IC like this? -_-

RussB

<center><img src="http://pictureposter.audiworld.com/49589/audi1991200qalternator.jpg"></center><p>
The star portion of part 18 in the above illustration can be manipulated with a long arm 22 mm box wrench, to adjust belt tension, as you tighten the other bolts. As you rotate the "star", it walks up and down the teeth in the slot of part 17, tightening or loosening the belt.

Often the teeth of the star portion of part 18 (it's just cast metal) and / or the matching teeth of part 17 become damaged, which ruins their functionality. You can buy new ones from an Audi dealer.

Once the belt is tight, use a 13 mm wrench to tighten part 18.

mcorrow

Brushes on the Voltage regulator may be worn, check that first..

Kneale Brownson

Those teeth usually get damaged because folks forget to loosen the bolts that help hold the alternator in place, especially the backside #8 in the illustration. It's also a good idea to loosen the bolt that holds the other end of the item #17.

rooster 2

disconnect the battery. Remove voltage regulator and brush assembly from side of the alternator. That is one nice feature of a Bosch alternator. If brushes are worn, then just replace the brush assembly. It is a whole lot less money then replacing the entire alternator.

koolhand

If I recall correctly, when starting up with the initial problems mentioned above, those lights came on until I tapped the accelertor and they went out. When problem returned later, the battery and alternator idiot lights came on.

That also brings me to the other question...whats that Bosch Application Notice B-85 about? It was very wet out yesterday and the notice mentions something about those condition pertaining to their alternators.

Thanks guys, apprectiate the direction. Will do when the winter storm passes. Car did start and behave fine this morning.

Bisqueth

plug joining the blue wires above the alt, near the positive terminal under the hood...i was having a similar (noncharging) issue, and on suggestion from the sjm site i cleaned and treated the connection with contact cleaner and radio shack contact gold...now it charges like a champ.

87 5ktqa (about to uberboost)
87 citroen cx 25 prestige