Not charging. At rest my battery measures 12.5v and then with the engine running it is pulled down to 12.3v. I tested for AC with the engine running and got 0.2vac, so I don't think it's the rectifier. I tried grounding the alt case with jumper cables, and I cleaned the positive connections.

Sitting in the car, at idle the needle indicates way low, and if I rev it up to 2,500 or so it moves up about one needle width, still way low.

Question 1: Before I rebuild the alternator, how do I test the exciter wire? Is it just a dc voltage or does it get some weird PWM signal or something I can't test?

Question 2: If I decide to rebuild with a self exciting voltage regulator, do I just hook the same harness back up like normal or do I have to change or remove any of the wires coming from the car?