Let's take this hunt in a sequential manner.
1. Looking at the wiring diagram, we see that the signal enters the coach either as the connection to the shore cable provided by the RV park, or as an off-air antenna contained on the coach roof. The selection of which of these two is done by the antenna switch/amp (which in the case of my coach is a single device panel that has a small LED indicator and a push button switch, along with perhaps a 12 volt power outlet.) The coax connector on this panel is the output of this selection action...as I recall the off-air antenna is selected when the indicator is lit. Some of these selectors have a signal strength amplifier built in as well.
2. The output of this selector then goes into the splitter to be distributed to all the devices in the coach entertainment system that consume RF television signals. The diagram above shows these destinations as the front TV, the bedroom TV, the outside TV and the FM signal input jack of the radio/disc player/surround amplifier unit. If you have a VCR in the system, you may have a connection to it from the splitter as well...
3. Notice that the satellite connection does not use this splitter -- that coax is a much different type of signal and runs directly from the roof mounted dish (if fitted) to the satellite receiver. You will note that the output of the satellite receiver is "baseband" video and audio, and these signals go to the AVS 100 distribution selector to be sent along to the various TVs in the coach. It is these baseband audio and video connections that you describe being active in your coach in your initial post.
Do you presently have any off-air or park connected video sources active in your coach? If so, simple inspection of the diagram should allow you to envision how the components are presently configured and the switches set.
Let us know what you find...
2007 Tour Master T40C
Acura MDX toad
"It takes a great deal of time to recover from any improvement..."