Hi Jesse -- I don't believe you will find any switch as such. I might not have it all in this summary, but 110v AC only goes to your Univolt, air conditioner, refrigerator and your 110v wall outlets. An original Dometic type fridge is either two-way (110v AC or LP) or the less common three-way (110v AC, 12v
DC, or LP). Is there a master switch of some sort by the door?
Everything else you see inside/outside the trailer runs on 12v -- it will draw from the Univolt if you're plugged in or else it will draw off the battery. All the lighting is 12v. The furnace, water heater and water pump run off of 12v, though the fuel for the first two is LP. The two systems are isolated from each other with the Univolt being the converter from 110v to 12v; the Univolt also supplies 12v to recharge the battery (in the best conditions -- old Univolts can cook a battery dry if you stay plugged in).