Hi Jim,
A bit of a long answer to a short question . . .
We have the Garmin RV760LMT. A great nav system with lifetime map updates included and lots of useful built in features. I have one Garmin B20 backup camera on the back of the truck (installed and working great) and another for the back of the RV (not installed yet).
The camera is definitely a "back up" camera with a wide angle lens but not much depth of field. It does have adjustable distance bars that can also be turned off. The transmitter box is separate from the camera and is the unit that needs 12V power. On the truck, I have this mounted in the space behind a rear tail light and it transmits through several layers of metal to the dash mounted nav screen with never a hiccup.
Garmin cautions that from the back of an RV to the dash of the truck might be too far for reliable wireless transmission. They sell a 50 ft camera extension cable. My plan is to hardwire the camera on the back of the RV to the transmitter in the front storage compartment. Easy to power the transmitter here, and direct "line of sight" to the nav screen. I would like to have the camera up high, but with its limited depth of field and no easy way to run the wire, a bumper mount (like I have on the truck) may suffice. Certainly sufficient (maybe even better?) for backing up and quite capable of finding the tailgaters siting back there on the highway.
I power my truck mounted cam from a plug into the trailer power connection. When I hook up to the trailer and switch this plug for the trailer plug, this will switch power from the truck cam to the trailer cam. According to Garmin, I may have to "pair" to the different camera each time, but there is a button on the nav screen base for this.
Rob
