First off, belated Welcome to IRV2!
Check under the dash for the switcher/controller for the cameras. It will be a black box with three RCA cable connections and a couple of wires for the turn signals. It's very common for one of the RCA camera connectors to vibrate loose.
2017 Phaeton 40IH XSH Maroon Coral - Power Glide Chassis with IFS
Previous '15 Tiffin Allegro RED 38QRA and '06 Itasca Sunrise 35A
'16 Jeep JKU Wrangler Sahara or '08 Honda Goldwing