Suddenly after 8 years a strange electrical issue

[Automan]

Sorry in advance about this question since it might be considered as a dumb question. A good ground is found on the frame only since the rest of the car is fiberglass?

[Tommy]

Originally Posted by Automan

Sorry in advance about this question since it might be considered as a dumb question. A good ground is found on the frame only since the rest of the car is fiberglass?

That is correct. To be doubly certain, run a jumper wire from the negative battery terminal as your known good ground.

Second thought: I'm not familiar with your particular light fixture. All fixtures on fiberglass bodied cars have to be grounded, usually with a wire. Sometimes the wire will attach to the body of the fixture if it is metal. Other times it will be one of the wires that goes to the socket for the light. On standard wiring, the ground wire will be black.