towing behind fifth wheel camper

I have done both ways described above. I prefer the method of coming back from the junction box at the pinbox. It requires more wire, but you aren’t splicing into existing wires that might cause other issues. You also want to make sure the hitch you have at the back of the 5er is properly mounted and sturdily built. It not only needs to support whatever you are towing, but it also needs to be built so that it doesn’t over stress the 5th wheel frame. There are a lot of side forces acting on the 5er frame when turning due to the typical long overhang behind most 5er axles.