If you are using the refrigerator on propane you need a constant source of 12volt power. The refrigerator probably does not have a pilot light. If you are using the water heater it too will need power if it dosen't have a pilot light.
2011 Eagle 330RLTS with just about every option.
Dodge SRW 1 ton Cummins powered.
I was born with nothing and I still have most of it left.