Cherokee33

Hey guys I bought my jeep a few years ago and tried recently to hook it up to two different trailers, that I know are wired right to see if the existing wiring would work. It did not. The guy I bought it from pulled a pop up camper and I got to looking and it has a box on the jeep that is fed from all of the lighting on the jeep and power from the battery. The box is feeding the 7 way that has a right turn, left turn, and tail light wires currently. I plan on keeping the 7 way in, so would it be better to get in the box or get the box out and wire it straight through? I've never messed with any boxes like this one, so I was gonna see what ya'll thought.