AC Quit (and the fix) in my Pop-up
When we bought our pop-up used, everything worked. We were able to use the AC one time and then on the second trip it didn’t work.
Here is how I determined what the problem was and how it was resolved:
I plugged the trailer into my 20 amp circuit and plugged in a three light circuit tester into the end of AC cord. These are fairly inexpensive and are available at your local hardware store.
The tester indicated that the hot lead was connected but the neutral and ground lights were flickering.
Good news, this meant that the AC unit was probably fine but that it wasn’t getting the electricity it needs to run.
Unplug your camper from the power outlet before proceeding, if you are going to work on your electrical system!
After removing the two screws that held the wood cover in place behind the power converter I had access to the junction box for the AC power line. On my pop-up, this was located under one of the seats where the power cord enters the trailer.
Once the cover to the junction box is removed, there were three wirenuts; one on the black (hot) wires, one on the white (neutral) wires, and one on the ground wires.
The white wirenut was partially melted and the ground wirenut fell off as soon as I touched it. My guess is that these were not properly installed at the factory.
I re-twisted the white wires together and installed a new wirenut. Next, the ground wires were twisted together and their wirenut was reinstalled, the junction box cover was screwed in place and the cover for all the electrical wires was reinstalled.
Once that was completed the AC unit worked as it should.
Legal disclaimer: If any of your electrical system (outlets, AC, etc.) are working intermittently, have them checked out by an experienced electrician ASAP! A camper is no place I would want to be in the event of an electrical (or any other type of) fire.