Turn off your propane? If you are using your refrigerator, you may have a 3-way that can run off of your 12 volt supplied by your vehicle. Your trailer is a pop-up? Our pop-up had another switch on the thermostat to totally shut it off. Check to see if you have one. Ours was on the bottom of the thermostat.
Our pop-up was a Rockwood Premier 1907 so could be similar to yours.
2012 F150 FX4 Ecoboost, 2016 Surveyor 274BHS
2003 Yamaha FJR1300, Demco Premiere Slider
1969 John Deere 1020, 1940 Ford 9N, 1948 Ford 8N
Jonsered 535, Can of WD-40, Duct Tape
Red Green coffee mugs