Well, now that the side is repaired, I've been testing the other systems. Inverter is working, fan in it is a little loud, sounds like a playing card in a bycicle spoke.
Also found that the water heater is bad. It is a suburban unit, went to pull the anode plug and it snapped off. Drilled it out, ran a flush wand through it, and it kicked out a bunch of porcelain material, along with a lot of white crud, probably calcification from never being flushed out.
Lucky enough, camper was built with a water heater bypass, so turned all the valves, and put a few gallons in the fresh tank and ran the pump. Found the kitchen sink cold water fitting is cracked, and the faucet leaks at the knob.
Joy of restoring a 20+ year old unit. Gotta love it.