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Camper wiring , that I've dealt with was only 5 or 6 wires .
Depending on the rear lighting of the camper .
1 Running lights
2 Left signal / brake light
3 Right signal / brake light
This is probably how you camper is currently wired
5 Back up lights
6 Battery power or charge wire ; depending on the battery location ; in the camper or mounted in the truck .
Note: Battery charge wire and ground are most often heavier gauge than lighting wires .
A seventh wire in a standard Bargman connector on a truck is for trailer brake activation .
So if your camper has 7 wires ; I'm not sure what the manufacturer was using that seventh wire for .