I have a 1992 Ram 250 4x4 and the head lights went out. At first it was just the high beams then after a while the low beams went out too. I replaced the headlight switch and the headlights worked for a couple of months then the high beams went out followed by the low beams a while after. I figured the part was probably bad so I replaced the switch again, but still do not have headlights, but I have running lights. I put a light tester on the wires going to the switch and have power everywhere except three poles labeled U, B3 & D on the right side of the switch. Does this have something to do with the dimmer switch? Or any suggestions?