If you mean to use it as a rear view camera besides just for backing up, you can switch the power to the camera or leave the camera on and switch the display.
Our camper has a "porch light" by the back door that can be left on to tap the camera's power into for constant 12v.
I don't know a good way to get the video wire to the display in the truck. I have a Hopkins wifi camera that works great and displays to your "device" when you select the Hopkins APP. You just put the "device" on your rear view mirror with elastic bands and good to go.
This one has those two guide lines you can select when backing up or leave off for driving. The camera also has a light you can select. The wifi works up to 40 ft so not enough for a 5er, but could use a booster in the front of the trailer. No issue with a truck camper for distance.
There is a time delay which you have to get used to, so you see a car starting to pass and he is already beside you. something to do with "processing time". I don't know if that happens with a wired system.
