I have an 82 Z28 with a lot of mods not much left that is stock.Last year my alternator went out and I had it rebuilt. But at the same time my radio which is not stock started to turn off and then back on. Also if the radio is playing and I pull out the light switch, the radio goes off and then back on. I have tries everything I know. I wired the radio up to the battery, I have changed the headlight switch twice. I switched radios and nothing changes. I do not know much about alternators but could it have been rebuilt wrong? The car starts find. I did put a meter on the wire to the radio and it was showing 12.5 volts, but when I pulled out the light switch it dropped to 10 volts. Any thoughts would be great thanks..

 

Sounds like a bad connection in the wiring that feeds the car wiring system, either from the battery terminals or at the starter.

 

Thanks for your thoughts, I think then was something going on with the groud wire.. works much better now, thanks again..