TT back up camera help

Here is what I did with my back up camera. I mounted it just below the rear center clearance light and wired it to the light. Ran the wires through the hole for the clearance light to the transmitter. Drilled a hole through the paneling to the inside and mounted transmitter inside the cabinet that was there. I also wired the screen to the parking lights in the truck. So all that I have to do so get a picture is turn on the parking lights. Also works for passing or getting on the interstate, as I turn it on and I can see what is behind the trailer.
I also put a switch on the screen in the truck, so if I use the truck at night, I can turn he screen off.

RF link that plugs into the camera is about $15 on ebay. Much easier than running wire.

I have no quality issues.

Run it straight across the roof and put a bit of Dicor every 10 or 12 inches. My antenna cable is secured with dicor.

If you don't want to run to your lights for power, as I see it, you only have a couple of options. 1. Run it down the outside, maybe on a ladder with zip ties down below the trailer and along the frame rails. 2. Drill a hole in the trailer and figure out how to run it down the inside back wall to the bottom of the trailer and along the frame rails to the battery.

Let me be the first to ask - why don't you want to get the power from the lights?