Gordon, it won't hurt anything to use a DMM to test the wires for continuity when the plug is pulled from the inverter. You can try all combos (I believe there are 6 or 8 wires going to that plug) with switch on and off and see if you can find the pair the switch is connected to.
Anotherthing, can you get at the back of the remote switch on your control panel in the coach? That will tell you a lot if you can see the wiring there.
Stewart, Brenda and kids
2008 Newmar Canyon Star 3410