Generator Problem...but I just read 6 pages of generator light threads...
 

And it seemed like half of them were 74 CIS cars. My 74 became harder and harder to start, then started running rough and wouldn't start. I thought the coil was bad and swapped it. I thought the CDI was bad and swapped it. I finally reset my points and it runs fine...but the generator light is on. I check voltage across the battery terminals at 2000 rpm and showed 12.56 volts. I figured I would check the alternator...local shop said it was bad and swapped me out for a rebuilt exact replacement. Installed it today, car started right up, but generator light was still on. I checked voltage across the battery terminals...you guessed it 12.56 volts at 2000 rpm. Could something have happened when I was swapping the CDI and coils around? When I regapped the points...could something have gone awry? I have followed my wiring diagrams and everything is hooked up correctly and ground straps are in place. I checked the back of the instrument and the wires don't seem compromised. Something seems fishy...I know when the VR dies, the voltage acroos the battery terminals goes up. Is it possible for the VR to die and not have the voltage go up? Belts are tight...hmm:confused:

Thanks

Speedo

If your wiring is fine the next guess would be the VR. I don't think there is only one way a VR can fail. If the VR passes D+ straight to DF that would cause the alternator to overcharge. If the D+ terminal is internally disconnected inside the VR you would see what you describe: The light never goes out and the alternator doesn't charge. I would get a new VR.

Ingo

Ingo...you were right
 

I had an archaic Marchelle VR. I deleted all the old noise supression crap, installed an updated VR and the problem went away. I start the car and the generator light comes on...as soon as I apply throttle...2000 + rpm it goes out. Weird thing...I opened up the Marchelle VR and it all looked ok...nothing burnt.

Thanks again...

Speedo