hi, problem with alternater light staying on when the key gets turned off, car starts ,when i start car ,the light goes out , any idea,s why this would happen, thanks for the help . car is a 70 cutlass, friend of mine , thanks will.

 

most likely there is a shorted diode inside the alternator, the regulator contacts are sticking, or there is a wiring harness short. beyond that, you get to open a can of worms.

take the alternator off and have it tested, if you have a spare, good regulator, swap it in place of the existing one(make sure the body ground to the regulator is clean and tight).


bill