Jim, I had the same problem with my lights when I got it put my jeep back together. My issue was a chassis ground problem, because everything was painted all nice...lol. I ran a ground wire from the body to the frame and also a seperate one for the front grill to the frame. As well as one directly from the battery to the frame....That fixed it for me....good luck..
Another thing to note if you run a Aluminum Radiator you should run a ground wire from the radiator to a chassis ground....this keeps them from corroding from the inside out....