hello, I have one of these rear view cameras fitted to my head units, not sure what head unit you have but from my experience, I would not connect it to come on when the gear is in revers, what you will get is the screen go on and off as you try to do a three point turn or go back and forth in to a space, as the screen goes off once you are out of reavers and takes a few more seconds to come on once you are back in revers, I can a sure you after one week you will be pulling your hair out or not bother using it. with my head unit I have the factory fitted reversing camera plug and two Aux in plugs, I connected my rear view camera to one of these Aux plus, so when I'm reversing I can if I wish switch the camera on and it will be on till I have finished needing it.
not sure about your camera but mine came with 2 cables, one for the video signal and another with a black and a red wire for power, both were long enough to thread from the back of the car to the dashboard, myself I wired my camera to switch on when the head unit comes on, so one selection of the Aux in and the rear view camera is on, I'll have a look and see if I have a youtube clip I can link you to