I don't think it's the ground, because I can apply 12V + to the gray wire and all the lights come on. The problem is that the gray wire plugs into nothing. Is it possible I got the wrong turn signal switch? I had thought the gray wire gets its power somewhere else. I could jumper a wire to it for them to work, but then the rheostat on the headlight switch would be defeated and they would always be on full bright.