one wire alternators are great.....


for forklifts & tractors. A 3 wire setup gives you a better system. The alternator charges when it starts spinning, not waiting until you "wing" the motor. Also, with a 3 wire, the regulator gets a voltage sense signal, and actually knows (about) what to charge, as opposed to the one wire, which charges at a predetermined rate.

Take your test meter & check the alternator, once you have the alt spinning enough to charge. It should be 13.8-14.2 volts. If so it's operating. Next step would be to have the unit checked at your local parts store. If they have a good test unit, it should be able to tell you if you have a bad diode.

While you're at it, have 'em load test the battery as well.