Well, after being sick for almost 2 weeks i finally got to mess with the truck a little today. I replaced the Headlight switch, courtesy switch, dimming switch, all the pertainent relays, the pertainent breakers. I cut out the old spliced rear light harness. I added a junction box in the rear with the trucks "factory 4 wire rear harness" in and 7 wire out to the trailer connection. The breaker / relay will not trip now. and the forawrd lights work correctly, so i think the problem was in the old spliced harness i cut out. But I haven't hooked the rear lights up, as I ran out of eyelets. I noticed this truck has a 4 wire rear light harness instead of 7 wire... is this normal?... The truck only has red, black, white, & brown rear light harness. The mack rd basic wiring diagram #8-50 I found online shows the rear lamp wire colors including green and yellow for the directionals, like the regular 7 wire trailer wire. Although, the wiring diagram also shows a small 4 stud terminal strip with green, red, black, & White going to the rh and lh stop,tail,dir,& backup lights with the black wire splitting to both lamps. So is the 4 wire red, black, white, & brown rear harness corrct?, if so, which will connect with the 7 wire? The diagram shows the 7 wire as: yellow - left directional, green - right directional, clearance - black, tail - brown, red - stop, ground - white. This is like the regular 7 wire sytle light hook up. If this 4 wire tail harness is not correct I will run new 7 wire cable from the front firewall terminal strip following the wire diagram. Any ideas or tips? Thanks, & happy new year!, Deo