I would check the voltage at the pedestal, also the breakers low voltage can and will cause a problem, and in some of the older campgrounds there in a voltage drop about the time everyone gets back and turns the appliances on. I am assuming that you checked the breakers inside the unit.
2002 Rockwood Freedom 2318G
2004 Ford F 150 5.4 liter
3 Chihuahuas Sammy, Delilah,Gypsy