Last month we went camping. The first night we camped in the parking lot as we couldn't get into the camping area. Everything worked fine off the battery
(a few lights
, the water pump, the fan). The next day after we drove up a bumpy road to the camping area, nothing came on. I had my mutli-meter, and the voltage at the fuse panel read 3.7 volts, and was 12.5v at the battery
itself. I figured that there was a loose wire that jarred loose.
Very odd I thought, but solved the problem by bringing the battery
inside near the fuse panel and wiring it directly to the fuse panel with some extra wire. Everything worked great for the weekend.
Today I was trying to troubleshoot the problem, thinking I had a loose wire/poor connection. With the AC plugged in, I got 13+volts at the connection for the battery in the front of the trailer. The battery read 12 volts. I hooked up the battery and unplugged the AC power and got nothing. There was no voltage at the fuse panel. I unhooked the battery, plugged in the shore power, and took another reading. 13+ volts at the battery connection.
It seems that if I'm getting 13 volts at the battery connection in the front of the trailer that the wiring is fine. I just find it bizarre that I get no voltage when I connect the battery and check the voltage at the fuse panel in the back of the trailer. I did have the fan and lights
switched on when I tried taking a reading for the battery. Is it possible that the load on the battery caused it to drop to 0? Of course, this doesn't explain why hooking it up directly last month worked fine (and why simply driving up the bumpy road caused it to stop working).
Tomorrow I'll hook up the tow vehicle and see if that powers the trailer and what kind of reading I get.
I'm confusing myself just writing this, so I apologize.