jkbpeavey, I believe the coax connection you see in on the OTA antenna power supply and switch. If so that is an output.
Hard to look at the drawings there are three different models of the 31KE in 2016.
It does look like there should be a composite video (red, white and yellow) cable in the cabinet above the passenger seat.
What is the number after the T in the coach serial (1,2,or 3)?
Also what cables are connected to the back of the TV?
Grant & Pat
2014 Adventurer 35P
2021 Rapid Red 4dr Bronco OBX