I am stumped. My truck won't light up the right side of my trailer lights. I didn't really realize this until today when I bought one of those light bars that go under the tailgate and above the bumper and only half of it lights up. I have no idea where to even look for this problem. I didn't think a fuse would have anything to do with it but I checked just incase and they are all ok. The guy I bought the truck from has lights all over he had a 3 bar light under the tailgate which I took off to put on this light bar he as 4 extra reverse lights for extra lighting he has a full alarm and remote starter system he has lights on the toolbox under the dash there are wires every where I don't know where to begin do you guys have any idea? I thought that the same wire included both brake lights that's why I'm confused. Any help is appreciated thanks guys.