That sounds the same as my trailer. The second unlabeled connector should be the cable connection. If you connect cable there, you should be able to watch cable in the bedroom. Make sure the Winegard switch is turned off. There is probably a second, unlabeled connector at the main TV. You can connect the main TV to cable there.
I have a drawing, that I made of my trailer cable system. I think it is on my work computer. I'll try to post it tomorrow.
Keystone does not label any of the cables or provide a diagram.
