Originally Posted by keith460
Yes a ground wire and no also. You are referring to the black wire coming from the headlight switch wiring harness and it supplies the ground path to the factory OEM under dash courtesy lights. It is not actually grounded until the headlight switch is turned completely to the left until it "clicks". The courtesy lights are always powered or "Hot At All Times" but are not grounded so they do not light up all the time. When you turn the switch, then the path to ground is made and the courtesy lights turn on.
Roger that. Thanks. I am going to heed previous advice and clean all connections good and retry. If that doesn't work I'm assuming it's a grounding issue. I guess the next question is, does the light switch ground itself to the dash when it is installed? If so, how does one bench test it before putting it in?