I'd like so more specifics. My 71 has a bosch alternator which is acting up. Puts out about 13.5 volts when first started, then drops and the light comes on, sometimes goes out at idle. Sort of a minor problem since the car sat for 11 or 12 years but I have to get to the bottom of it soon. I'll try the zap the field routine to decide if I purchase a regulator or replace brushes. The GM replacement might be the cheaper way to go in the long run. I'll check the archives for past solutions too.

Mel