Only a guess, when you pulled the wiring loose, you caused a short that tripped the main breaker for 12 volts, out on the tongue. Could be an auto reset model, and running the genny had nothing to do with it, but only time allowed it to reset itself. You mentioned none of the c/b's were popped. The house looking circuit breakers are just that, AC voltage only. The fuses are DC voltage only. There are one or two, or more, 12 volts circuit breakers, usually somewhere under the tongue or king pin, that handle 12 volt power to the camper.
There should also be a rest button on the detector that you can push, that will shut it up for a little while.
2012 Ford F250 ext. Cab 4x4
2002 Jeep Wrangler Sahara
2008 Yamaha V-Star 650 Classic
2008 Work and Play 18LT