Just installed a backup camera on my F-150. The camera works, but not as intended. When wiring everything up with the new stereo, I hooked everything up on the camera to the stereo to make sure it worked before running and zip tying the av wire along the frame. I had the camera wire plugged into the “cam input” plug on the back of the stereo, put the truck in reverse and saw nothing. I moved the plug to the AV slot and still nothing, but as soon as I plugged it into the AUX input I could see the camera image. When I shifted to park, the display went blank as it should. The problem with this is