Make sure everything is turned off in our camper that runs on AC power. Then turn on all AC breakers. Even though you are plugged into a 20 amp service, the power management in your camper breaker panel will manage that 20 amp service. Now, one by one, turn on each appliance, item and see if it works. Then turn it off and turn on the next one. Power management will direct power to the right breakers for the item you are turning on. If everything works, just make sure all the breakers stay on. When you plug into a 50 amp service the next time, everything should be working.