[logician]

Thanks guys for the replies. After a few inquiries, I'm pretty sure that the alternator was transferred over from the original 2.2L engine so it would match the regulator. I believe that would make that alternator one of the Motorola/Marchal (sp?) ones.

I've done a bit more investigation, and measured some voltages. I find that when the alternator is overcharging at 16.5V, the D+ voltage on the regulator is at 15.5V -- one volt lower than the B+. As I understand it, that really shouldn't happen, since the B+ is downstream of the D+, and after an isolation diode in the alternator. Thus the B+ voltage should be about a half volt lower than the D+, not the other way around.

Something is really fishy about the whole thing, and I'm suspecting a bad connection somewhere in the D+ wiring that is causing a voltage drop. I'm going to pull the alternator later today to have a look at the connections back there.

-Juan