Reverse lights work great with no trailer. Hook up a trailer and the fuse blows. Replace the fuse, no problem until I hook the trailer up again, then the fuse blows. Is it just a ground or what? Thanks in advance.

 

I just had the same thing happen on mine....found out the reverse lights on my trailer were grounding out intermitently. Run a jumper wire around the original reverse lights wire and see if it still happens

 

yes check the trailer! LoL my trailer has a ghost short that i have not found yet and every so often it acts up and the thing will blow a fuse and leave me with out lights. the only other wire issue i have is every time i go get the cows from the summer pasture i rip the brake wires off the axel so iam in the drawing stages of coming up with a way to bolt conduit above the axel to run the wires up and though