Curtis gave you a good starting point. I had a similiar but not exact situation on mine. Do you have the seperate round lights on the rear or the single long ones? I finally traced my problems down to a high resistance ground somewhere in the wiring. After much delebiration, I looked in the wiring schematic and found the lead numbers and where they multipled. I then went there and cut the ones to the rear off and ran new ones from the other side of the connectors. They have worked great ever since and that was in 1997.
Ron
