The Master Switch UP position allows you to use all DC powered devices, such as lights, fans, furnace, water pump, and the DC power to the refrigerator if wanted. It is the "Camping" position. It DISABLES the lift motor so the top can't accidentally be lowered on you while camping. It also has a center position, which is the "Travel" position. This disables all DC powered things AND the lift motor, so nothing can activate accidentally while you are traveling - BUT it leaves DC power on to the refrigerator, so you can keep things cold while underway.
You have an extra switch in the white one on the right which I don't have. Do you possibly have a "tip-out"? If so, it MAY allow you to activate the tip-out when camping but prevent it from accidentally activating when underway or when raising or lowering the top? It MIGHT be a porch light switch, but mine is on the upper wall near the door.
Someone with your model trailer can tell you for sure what that other white switch is for.
Hi-Lo 1707T - Tire Minder TPMS on Tow Vehicle and Trailer, 300W Solar Battery Charger, Equal-i-zer WDH, Progressive Dynamics Converter, Fan-Tastic Fan
2014 F150 Platinum 4x4 3.5L EcoBoost SCrew