The wire looms used in RVs often contain extra wires for options you may not have. Most wire looms have identifying labels printed on the wires themselves. If your's aren't, either hope someone on here can share a wiring diagram, or use a signal tracer to connect to the wire and see if you can find it again at the end location.
Bob & Donna
'98 Gulf Stream Sun Voyager DP being pushed by a '00 Beetle TDI