red, white, green wires where do they go? and to what?

Try the fridge on electric when plug in
You have not mentioned year and model of motorhome
Those wires might go to the propane system
Depending on year and builder Some RV's have a 12v control valve for the lp system located at the tank in the main lp line
With out power you get no propane, so no stove, heater, no lp too water heater or fridge