This is only a guess but here goes. It's based on helping owners of a Winnebago Class C get their TV working after a paid "tech" loused it up trying to install a DTV Converter Box.
OK, Cut to the Chase: That coach (and I have no idea about yours!) was pre-wired for Roof-Mounted Satellite. But it was not equipped with that system, and I remember a Jumper between two panels. In the Winne's case, those connections were behind the panels. My mission was to get these good people's TV working again, so I did't try to figure out the What-If's of it. This is where Winnebago (COACHES, NOT Towables!) shines. We looked up the wiring diagrams on their website and set about putting it back the way it was built. Undid the botch job the owners paid about $200 for. Then it worked. Amazing!
So, my guess... It's set up for some feature you don't have.
EDIT: For the Good of the Order, I don't believe the person I refer to as "Tech" was an RV Tech. This was 5 years ago, but I believe they went to a home entertainment store or the like.