Alternator OEM Audi or Bosch

Volvo tech here, Bosch. Just replace the whole thing, it's not worth doing the brush job only to find that you should've just done the whole thing first.

I ordered the genuine Bosch alternator for not even 300 bucks and installed it myself for him still good a year or so later and it was a very easy job

Get the Bosch, including the warranty from them, and be done.

Bosch has a support site that shows what alternators they recommend for your VIN number. AL20X (65A) and AL172X (65A) are the two Bosch shows. However most of us know the original was a 90A unit AL30X.

After getting mine rebuilt 3 times and still having the same problem, I ended up getting a Bosch factory rebuilt one. Cost-wise I don’t think it was significantly more than one rebuilt by a shonky auto electrician and in the long run would have been cheaper.

Mine was my alternator. Never had battery issues but once I replaced it with a new bosch all the electrical gremlins the car had went away.

13V is normal for a stock Bosch alternator. There are 14V or adjustable voltage regulator available as a replacement.

I took the alternator apart as well, but it's quite worn and a new one does not cost a fortune, so it's not worth it to refurb it.

On my '93 240, I used a 740 external regulator Bocsh alternator...100amps...the problem is is that the voltage regulator takes a dump, which leads to people replacing the entire unit (like me years ago).

FWIW I bought an oreilly\u2019s remanufactured for my e34 a few years ago. It failed and was replaced twice in two years until I just bought the Bosch from FCP. No issues since.