Alternator Bosch or OEM BMW

90 amp Bosch alternator I'm using for my 8V motor. I upgraded the +12V wires to 4AWG from the alternator to the starter and the starter to the battery. Make sure your grounds are good. Battery to frame and to motor. And alternator to motor.

Have a look at Rockauto.com

They have Bosch remans in different sizes.

If you go for a bigger output alt, add a fat cable between the output and the battery via the starter terminal, as the two wires that carry current to the battery via the starter terminal will then be undersized. The cable cost is minimal.

Buy the Bosch it's a direct OEM REPLACEMENT alternator it's probably still going to need programmed via vcds to allow the computer to adapt to the voltage change of the new alternator

In your case I would say just buy a new replacement alt from a name brand like Delco Remy or Bosch, none of this parts store rebuilt junk, you'll just be doing the job over again soon.

Bosch, Valeo, or Denso would be my top choices. Don't get a Chinese one. Shit won't last at all.

My alternator went and I never had any lights, just weird electrical gremlins and batteries dying. Replaced it myself, took maybe 2 hours and the part was like $150 after the core return

I've replaced the alternator Bosch 0124615028 with an identical part number one. Then I replaced the F00M-145-435(or 385 depending on where you look) regulator on it with a AS-PL ARE0075P. Both regulates to the same voltage, 14.2V.

Even brand name remans like Bosch and denso are suspect but generally much less so.

We were on our way back from a daytrip when the M3's alternator decided to give up the ghost about 1.5 hours from home.

I was driving the Mini when the engine began to struggle at idle and then shut off, refusing to restart. The starter engaged but hit a wall of resistance. After getting it home, I found the alternator was completely stuck. The one I replaced was a Bosch. Its bearing had failed catastrophically, and the pulley would not move.