Alright, I've been away far too long. I'm back and need someone who really knows the wiring on these trucks. Here's the situation; both truck turn signals and brake lights work on the truck but only the left turn/brake works on the trailer. Here is my thought process so far. The trailer is fine, tried two dif trailers and same result both times. The fuse (13 and 14 if I remember correctly) in the passenger compartment is ok because one fuse per side for l or r turn, trailer turn and both brake. On to the power distribution box where I have switched the relays, both of which 'click' when the hazards are on. Both of them make the left trailer turn work and neither makes the right wink. The fuse in the power dist box can't be bad because one fuse (100?) Works both lights and only one is out. Ok, what am I missing? I am thinking chafed wire between cab and wiring harnes for trailer. Is there anything I need to check before I put a meter on the wire and try to trace it back to the cab and see where it gets hot? Anyone know a suspect chafe point for that wire if it is the case?