Originally Posted by mark0224
Battery's dead, got jumper cables or battery charger? This would be first Idea. If you have any battery left you should hear a clicking sound from the starter solenoid. I never had a Class A or C but I don't think you can start the engine as long as your levelers are down, I think its a safety thing. Do you have a generator? Will it start at all, can it be started manually? If you can start it you should be able to get things going.
The OP has no power to the dash and he said "all of the sudden". Even with a battery that won't start the engine, he should have power to the dash. It sounds like he blew a main fuse.
I always extend/retract the levelers with the engine running. You don't want to put that much strain on the battery. However, with the engine running you cannot extend the slides.
The generator is part of the house side...not the engine side.
To the OP, don't get too much into the weeds with this problem. Check your battery connections, then check all of your main fuses in the engine compartment.