Alternator Light stays on......

I have a '79 R100RS that has started giving me fits. Not long ago the alternator (GEN) light started to glow increasingly as the RPM increased. It would not illuminate at idle. I have replaced the alternator and the voltage regulator. Now, the light stays on after the machine has been turned OFF!!! I have disconnected the battery until I can figure out what the heck is going on here. Has anyone experienced anything like this??? HELP. Thanks.

Diode board! Be certain to disconnect the battery when you remove the front engine cover (ignition/alternator/diode board) because if just brush the cover on the diode board it will zap just to spite you. It sounds like there is an isolation diode on the board that has shorted, that's what's causing the generator indicator to stay on. The indicator becoming brighter as the engine revs up would also point to at least one rectifier that's blown out.