I have the Garmin RV GPS that came with a camera. I just made 2 separate power points and mounted them under the rear bumper. One is an always on power that is connected to one of my upfitter switches and the other is connected to my reverse lights. When not hooked up to the trailer I just have the camera clipped to my plate with the reverse power hooked up. When the trailer is connected I just mount the camera on the back of the trailer, I have an extension already ran underneath the trailer, and have it hooked up to the upfitter switch power. That way I can monitor behind me anytime I like or have the GPS display up. Works very well and takes all of 15 seconds to swap out.
Dwayne and Susan
Jiro and Phoebe-4 legged family members
Mike and Dana - Traveling buddies
2016 Ford F350 XLT 6.7 Powerstroke DRW 4X4
2016 Brookstone 395RL