[Morris]

Seems to me that if you have the one wire alternator...you could take a jumper off the alternator and go to one side of a lamp.....then on the other side of the lamp...connect to the battery......that way when you turned the ignition on you would see the lamp on from one side being hot ...then when the alternator started spinning and had a output the light would go off because you would have a 12 volt potential on both sides of the lamp....if the alternator started going bad the the battery side would be hot and the alternator side would be ground so the lamp would light.......I think ��