We have a 2013 Bounder with the same issue on the left side. The cable comes in through the mirror base and side wall(maybe a foot or so), and connects to a longer cable that runs to a video-in block(not sure if that's what it's really called) mounted to the firewall. It unites the left, right and rear cameras. From there, it went to the stereo. I've since added a monitor on the dash, as looking down at the radio was inconvenient and dangerous. Anyway, I tried swapping right side for left, to test, and the extension cable/block were ok. I've since been informed that it's probably a 'bad camera', and the only option is to replace the mirror head, as it's not serviceable. I emailed Velvac and got the 'new' part number. Haven't pulled the trigger yet, as I can see just fine down the left side with the mirrors, and can spend $300+ more usefully.
