When you wire the transmitter module for the Garmin camera, there is a wire that connects to the backup light wire on the vehicle. Thus, when you put the vehicle in reverse, the camera comes on and the GPS image is replaced with the camera image on the screen. The range of the transmitter is not sufficient to reach all the way from the back of a towable RV and the system was not designed to be a full-time monitor - just a backup camera.
That said, I found the image quality of the Garmin camera to be less than stellar. I just traded trucks... kept the 760LMT but didn't bother to take the camera off the old truck.
Rob
U.S. Army retired
2020 Solitude 310GK-R
MORryde IS, disc brakes, solar, DP windows
(Previously in a Reflection 337RLS)
2012 F350 CC DRW Lariat 6.7
Full-time since 8/2015