Still a problem with tail/running lights

[msubobcats]

I replace the fuse and the tail/running lights work fine. But when I go out on the streets it will pop the fuse. Am I looking for a bare wire somewhere... And which color wire should be the tail/running lights... Really cannot afford to take it to a repair shop. No telling how long to trace out the issue.

So my thought is the vibration is causing a wire to short out somewhere on something???

Thanks for any advice.

[JRTJH]

The "tail/running lights" should be the brown wire on pin position #3 on the trailer umbilical connector. It is the first pin CLOCKWISE from the keyway index. If the lights work when you replace the fuse, then with travel/towing the fuse blows, I'd suspect a pinched wire somewhere along the frame.

First step, at least for me, would be to remove the cover from the umbilical connection box and check to make sure all the connectors are tight and not corroded and that there's no "stray strand of wire" hanging out from under a nut.