I have aftermarket license camera on truck that is hardwired to radio/monitor.
Mounted another camera on camper. It (video) is wired to a transmitter, triggered by camper bu lights. Its receiver is mounted behind truck tail light.
The power lead from truck BU light that ran to camera rerouted thru 3way switch. From switch 1 lead goes to trucks BU camera, the other lead goes to camper receiver. Switch selects which camera is powered or sending signal.
On the video cable to monitor unplugged truck camera at rear, install an RCA 'Y'. To it plugged in both truck and camper receiver video cables.
All I need to do is flick the 3way switch to have wanted camera.
