I apologize for bumping this old topic, but I have done quite a bit of research on this, so I want to share my experience.
My 24rls came equipped with a base mount for a Furrion camera on the rear of the trailer, but I didn't want to spend $400 for a wireless camera with a small 4.3" monitor. Over the years I've tried several backup cameras, but none have ever worked out long term. I mainly wanted to use them to see what was behind me when changing lanes and turning. One eventually got condensation inside the lens, a couple were always intermittent and all just had screens too small to be practical.
Last year I picked up a Good Sam (Rand McNally) 7735 https://wheelstips.com/best-rear-view-camera
It has a 7" screen. I knew it had a video input but never got around to using it until recently. Thought I would list what I bought to add a rear view camera to it. I know it would be more convenient to have a permanent mount, but I don't want another camera sitting out in the elements 24x7 and eventually losing its seal, so I used the large suction mount I wasn't using that came with my GPS. I added a safety strap in case it lost its grip but so far some very rough roads haven't made it come loose. It is mounted to my trailer's rear window.
Good Sam - Rand McNally 7735 GPS (Camping World)
20FT GPS Camera Video Cable 2.5mm Aux to RCA AV-IN Adapter
Pioneer Backup Camera ND-BC8 (Best Buy)
10' RCA video cable (Best Buy)
The Pioneer camera came with 33' of cable that reaches up to the hitch area. The GPS video adapter cable has 20' of cable that reaches from my truck's dash to the hitch. Then the 10' RCA cable is used to connect those 2 cables together when hitched.
The 7735 GPS detects when a video signal is present and displays a touch icon in the upper left corner. Touch it once and the rear camera shows. Touch the screen anywhere and it goes back to the normal GPS screen. 7" is a decent size to see what's going on behind the trailer. All backup cameras have a wide angle lens and focal point designed up close backing up, but the larger screen helps see what's going on a few hundred feet further back when planning a lane change.
On YouTube there are a lot of interesting videos on this topic, I will share with you, one of them, hope this will help someone. Good luckhttps://www.youtube.com/watch?v=iwhSWTnSaw0