my battery light came on in the dash today, i guess it means the system is no longer charging.,.so does that mean that either the belt or the alternator?? however i did just replace that belt...
Battery light Were you able to resolve this problem? I was a little dissapointed to see that nobody had posted a reply before now. I have a similar problem: Battery warning light came on intermittently at first, then today it stayed on. Whatever is going on seems to be getting worse. I'm taking it to the dealer tomorrow but would like to have some idea ahead of time as to what they'll say. Have you learned anything new about this issue? Thanks, Bill
hey yeah i figured it out. the alternator was only generating half the output it was suppoose to. i replaced it and it works great now, light went off! dont take it to the dealer! you save alot more just taking it to another place. its just an alternator. any one can do it. get your current alternator tested and then you will know for sure if you need it!!
Well, in this case, the car's still under warranty so I think I'll follow through with them. In the meantime, I've been doing a lot of reading on this issue and it seems that all the posts to various internet forums are split about evenly between battery, alternator or voltage regulator as the culprit. I'll let you know what happens in my particular case. Thanks for getting back to me.
Battery Light 2001 540i - I am have the same battery light issue as "billloyd". Any information on the diagnosis? Thanks,
Battery Light I'm sorry I didn't "close out" this thread with a solution response back in June of 2008. The short answer is: it's the alternator. The long answer is that I did take the car to the dealership the next day (it was still under warrantee). Unfortunately, this trip gave me my first opportunity to test the responsiveness of BMW Roadside Assistance. Yep, on the way to the dealership, the battery died -- and so did the car. The wait on the shoulder of the Interstate wasn't fun but was relatively short and when the guy arrived, he jumped the battery and I followed him on to the dealer. They gave me a loaner car and replaced the alternator and battery. They confirmed that the alternator was the culprit. So, like "chll69" wrote above, go to any reputable shop and have them do the work. If you caught it early enough, you may not have to replace the battery too. But, if you're like me, and if the battery has a few years on it, just replace both for peace of mind. Believe me, getting stranded on the Interstate is a bummer.
I just found this old thread with the same subject as my new thread. Is there a way to merge threads? Is there a procedure anywhere online I can follow to diagnose the charging system?
I ended up replacing the alternator (120A). It turned out it was only putting out about 11.5V charge and the new battery was probably covering up for it. Although I'm not thrilled about yet another repair on my E39 which I've only had a month, I have to admit that the system worked as it should to warn me of the problem. I just wish they wouldn't have eliminated voltmeters in cars. They are a good tool to keep an eye on the charging/electrical system, which is a system that can leave you stranded if it fails.
