DPD327

Jack, Replaced the alternator and that seems to have solved the problem. :)

Wish me luck!

Jack, I am thinking alternator as well.....brushes sound like a good starting point and inexpensive as a first shot....but the fact that there is good voltage for the first three or four minutes of run time (after engine start) is leading me to believe something more integral to the alternator....possibly diodes or ??? The full replacement of the alternator might be a better idea and if I can find one on the cheap, that might be the way to go....your thoughts?

Battery is good...tested it recently replaced about 2 years ago....keep the car on a battery charger in the garage.

Hi Folks, I have a 2001 BMW 740i with 7800 original miles (bought it new in 2001). I am trying to trouble shoot an electrical problem that looks like it might be alternator related. After starting the car, for the first 3 or 4 minutes the voltage output is pretty normal up around 13.7 V but shortly after that, the voltage drops and the battery light begins to illuminate on the annunciator panel and sporadically lights up. No codes on OBC. Battery is fine (in good condition but gets discharged once the voltage drop issues start). Checked the ground wire, check the belt tension all good there....any ideas? Could it be a bad alternator or perhaps a control module? DPD327