There is also a switch on the right side of furnace,under fridge inside the camper.
There is also a screw valve on the outside that might be shut when winterized( so a spider doesnt get all the way in
),slot of screw should line up with gas line(left/ right not up/down)
You can get a heat strip for the A/C unit easy install(E-bay)
Its works good, a soft heat with no thermostat control,save propane when pluged in