No power dry camping

Not hooked up to campground electric you will ONLY have 12V DC from battery....lights, water pump, furnace, fridge on propane, water heater on propane, radio, exhaust fan. That's it.

No outlets, TV, microwave, A/C.

Now if you don't have 12V DC stuff.....
Check battery disconnect switch in proper position
Check for an in-line fuse/circuit breaker on battery positive cable going to converter being blown/bad
Check on converter for 'large amp fuses' (Reverse Polarity) being blown