'64 Cad Generator light

Anybody have any insight...when I turn off the ignition and remove the key from my '64 Cadillac, the GEN light comes on & stays on after the car shuts off. I've been disconnecting the neg. battery cable as a temporary fix, but what would cause this?
Thanks
 
Bad diode in Alternator most likely cause. You can check with an Ohmmeter with the unit removed and disassembled. Unlikely a voltage regulator problem.
 
Alt. light

Inside of the alternator is a "tri-ode". It has 3 leads on it and when one side of it goes bad causes the problem you are having.
 
Back
Top