BMW Alternator Symptoms: Seeking Repair Cost & Shop Tips

Hey there! I had the exact same symptoms on my 2015 BMW 6 Series last winter at 155k km. Started with dimming headlights and weird electrical behavior, then got worse with starting issues. Initially thought it was just the battery, but turned out the alternator was failing. I replaced both the alternator and voltage regulator since they typically wear out together. It was a serious repair that took about 6 hours at the shop since they had to remove quite a few components to access the alternator, these modern BMWs are tightly packed. One tip: have them check the serpentine belt and tensioner while they're in there. Mine was showing wear and it made sense to replace it during the same service since everything was already apart. The symptoms you described are classic alternator failure signs. I'd suggest getting it checked soon before you end up stranded somewhere with a dead battery. Best of luck with the repair.

Thanks for sharing your experience! That's really helpful since it sounds exactly like what I'm dealing with. How much did you end up paying for the whole repair job? Also, have you had any other electrical issues pop up since getting it fixed?

Hey again! Happy to give you an update! The repair job cost me 960 € total, including parts and labor. And I've got great news, since getting it fixed, my car's been running perfectly with zero electrical issues. The generator replacement totally solved all those annoying problems like the dim lights and starting troubles. Looking back, it was definitely worth every penny to get it properly fixed. The mechanic was spot on with the diagnosis, and they did a thorough job replacing both the generator and voltage regulator. Really glad I took care of it when I did, rather than risking getting stranded somewhere. Must say, it's such a relief not having to worry about whether my car will start every morning anymore! The electrical system's now working exactly as it should, no more flickering lights or battery warnings on the dash. Let me know if you need any other details about the repair. I really recommend getting yours sorted soon, it'll save you a lot of headaches in the long run!

Thanks so much for all the info! I actually just got back from the mechanic today and wanted to update you. You were absolutely right about getting it fixed quickly. Found a specialist who really knows BMWs and got the whole thing sorted. Funny enough, my repair cost was pretty close to yours, ended up paying around 1000 € for everything. They also suggested replacing the serpentine belt while they were in there, just like you mentioned. Figured it made sense since they had to take everything apart anyway. The whole process took about 7 hours, but what a difference it's made! Started right up this morning with no problems, and all the electrical issues are completely gone. No more dim lights or warning signals, it's like having a new car again. Really appreciate your advice, it helped me feel more confident about what needed to be done. Now I can finally stop worrying every time I turn the key!