97 4.0 TJ manual Sport, orginal owner I've been having an issue where all the rear lights (left and right turn, 3rd brake light) flash when signaling for a left turn. Right turn signal works normally. Years ago, I installed a plug in harness for trailer lights, not the cut and splice kind. It hasn't been used in years, in fact, I long ago cut the wires off at the body and capped them. I figured the issue had something to do with that, so I removed the plugs for harness today and the wiring harness is back to factory spec. The problem went from being constant to being intermittant, and I can't seem to find a common condition that causes all the rear lights to flash. It just seems that every now and then, the left turn switch activates all the rear lights at once. I'm guessing a ground fault somewhere?