Many RVs have a B.O.M.B. (Box of Many Buttons) a switcher that takes various inputs (satellite, antenna, cable, DVD) and sends it out to the various TVs. You'll have to determine exactly what you want as inputs and outputs, then shop for the appropriate device. Amazon has many choices.
What type of cables do you have at present? Coax or HDMI? You might also consider a wireless system that might be better than trying to upgrade or repair wiring you presently have.