I was in craters of the moon a year or two back in Idaho,when a couple and their two kids pulled in and couldn’t get their trailer setup, they said they had recently bought it and couldn’t figure out why they were not getting 12v anywhere. This campground is a dry camp with no power. I took an electrical testor over and found the circuit breaker between the battery and trailer had failed. I think they were just about ready to cancel their trip when I showed them how to work around it and to replace the part at the next hardware store they saw. It got them up and running so the lights and fridge would work and they were very friend/social the rest of the night. I was glad I could help them.