Not sure what year you have, my 2015 has the up-fitter switches. Each switch has an inside wire and one under the hood. I have an 80 gallon fuel tank in the bed wired to one on the switches, truck has to be on and the switch on to run the pump. You can check polarity on the wires with a volt ohm meter, if back wards my pump would not pump. I'm sure the cameras going to be the same, I did accessory installs for SOB vehicles and they required proper polarity, today's LEDs are the same, many are polarity sensitive.
2015 F350 FX4 SRW CC LB
2017 Durango Gold G353RKT
New Mexico not new and not Mexico