Posted by Dwight Plucker on June 28, 2001 at 12:46:54:
My red battery "idiot" light started coming on and off the other day. I replaced the regulator on the back of the alternator and that did not solve the problem. Would weak diode in the alternator cause this? A local shop said it charged fine, clean all my connections and my light came back on within 7 miles. A local parts house has an alternator. I am planning to replace it this weekend unless someone has a better idea. On a 81 528i by the way.