I have a wireless system that works well for me. Gets a bit of interference occasionally but nothing serious. I had it installed by an auto electrician. He wasn't cheap but at least it was done professionally. It's wired through the ignition so it comes on as soon as the ignition is turned around to accessories and then stays on while the engine is running. In other words, it's permanent and not activated by selecting reverse.

As Wombat said, there are some very CHEAP (and nasty) systems out there!. I have a dual camera set up on my rig, one on the back of the van and the other mounted low down on the bumper showing the towball. The latter to assist in hitching up again, solo.. I opted for a wired system to bypass radio interference etc. Cost of the system, which included 2 cameras, a 7' screen, all cables and a coiled trailer connector was around  $240. Not cheap, but excellent value. Wired to accessories and switchable between the two cameras.   

Hi Yobbo2u, I will just put my comments up here as well for your consideration. We have hard wired our rear view camera as well as our revearsing camera. Wifi has too many problems with interference from other services as many are in the same frequency band. Hard wire eliminates all the issues with the only one beIng 12 volt supply to the camera and the video feed to your monitor which is easy.  just go to Jaycar and you can get a multi pin plug and socket that will do the job easy.

 

hope that helps

briche

I get my exercise the same way, hopping in and out, no camera's yet. I use a couple mate otherwise called a marriage saver. I line up the middle of the van with the middle of the back window ( have a marker) then check the distance and height. Make a couple of marks on the ground to work out how far to go back and the trailer mate just feeds the tow hitch over the ball if I'm slightly out and saves the bumper from damage. I can hitch up on my own with out help. This might help with hitching until you get the camera sorted out.