Argh, the dealer wants $81 for a new voltage regulator. I think my dad has a dead alternator with a working VR on it. If not, I guess I try the PartsShop, or drive around with a half-working voltage regulator. Maybe I'll pull it off and see if I can clean it up or recondition it a little bit.. that worked wonders for the power window switches on the console inside.
I pulled the VR out and immediately saw the problem - the little 120ohm resistor on the back of the VR had become unsoldered on one side and broken on the other side. I couldn't solder it back in, since the wire was broken right next to the resistor itself, so I got my hands on a replacement resistor, soldered it into place, and voila`! it works. There seemed to be plenty left of the commutator brushes.
I'm getting about 12.8V across the battery terminals at idle, and about 13.7V with the engine at normal operating speed. So, I guess I'm good to go.
I love this forum.
'83 240D, 250k miles
P.S. Finding a replacement resistor was a PITA. I went to Radio Shack, and despite their marketing slogan of "You've got questions, we've got answers" the only help they could give me is "We don't carry it, and we don't know where else you could go to get one." I guess a 49-cent resistor isn't worth their salesman's time.. not that he was busy doing anything else. I eventually went to the Electrical Engineering department of the university I'm attending/employed by, and they were quite helpful - the EE shop guy found me a working resistor and just gave it to me free of charge. Happy, happy day.
[This message has been edited by ncarter (edited 01-13-2000).]