Help with rear camera

Hello I am having a problem with the camera on the back of my 2013 Chateau 31A. The camera is connected to a Pioneer AVH-P1400DVD system. The issue I am having is the video seem very dark. Yesterday in the afternoon I was hooking up my tow vehicle to test all the connections(first trip with a tow) and the only thing I could see on the screen was the reflection of the sun in the tow's headlights everything else is dark. A similar issue happened when I test drove the rig before we bought it but I failed to asked what they did to fix the problem. I have checked to make sure the camera isnt dirty. What else can I try. Help we leave Thursday. I do have a call into the dealer and I'm also going to call Thor.

:h