muskeke (Dancer),
I have some experience with backup systems. With my previous trailer (a fold-down travel trailer), I installed a camera on the roof rack of my Jeep Liberty and then one at the bumper area of the trailer. They were both connected to a small color LCD monitor in the cab.
Here's a couple of pictures of that system.
For my current trailer, I have a different system but similar concept. One camera is mounted high on the rear cap of the 5th wheel and the monitor is mounted in the dash area. The monitor is capable of 3 cameras. I have a second camera that I have plans to mount on the truck, just above the cargo lamp/rear brake light above the back window.
As for the practicality of rear cameras, I will tell you that I am really glad I have mine. I would say that I derive the most benefit of using it while under-way. I do have fold-out trailering mirrors on the RAM but having a wide angle view behind the trailer and to a degree, the the sides at the rear is beneficial. Especially when changing lanes.
I find that it is actually less pratical for backing up. It is useful but since the lens is wide angle, your depth of field becomes distorted. Things are closer than they appear in the monitor. Still, you'll know if you're going to run over the utilities/trees/etc. at the campsite but your distance to such items is impaired.
What is nice about the current system is that it has audio too. So if my wife is behind the trailer as I am backing, I can turn up the volume at the monitor and hear her (we also use walkie talkies).
The system I have is the same that they use in the nicer motor homes. It's pricey but it is also a proven platform. I got the old and new systems from
Tim at RVCAMS.com Tim has great product at competitive prices and unlike many online stores, you can actually reach him and speak to him (real customer service!).
I also bought my (yet to be fully installed) tire pressure monitoring system from Tim.
As far as installing the camera on your trailer, depending on your skill level, installtion could be a bit challenging, yet worth it in the end.
On RV.NET,
Washboy wrote a good article on how he installed his (
pictures). He basically pulled off the center rear clearance light on the rear cap, fished a wire over and down to a tail light, then down to the underbelly from the underbelly, forward to the kingpin area. Depending on how your rear cap is constructed (framing members, insulation etc.) as well as how your underbelly system is (open, all enclosed, etc.), this may be fairly easy or fairly challenging.
Once you get the long camera harness from the rear cap to the king pin, you will need another harness to go from inside the cab to the rear of the bed. How you run that and dress it is up to you. Mine is flopped over the side of the bed and into the rear door. I have materials and plans to run it in plastic flexible conduit under the truck and into an electrical box in the bed wall, next to my 7-pin receptacle (winter project).
Best of luck to you and keep us informed as to what you end up doing.
Jim