Somewhere in the RV is a wall plate. it will have a 12 volt accessory connection which is next to useless. a Switch, A Light and an LED light This is what many folks improperly call the antenna "Booster" it is, however, among other things the "Source" switch for the TV's
Remove it from teh wall (2 screws) there should be 3 cables on the back. Looking at it from the rear, cables down from left to right they are ANT/CABLE/TV-2
Remove the center cable and hook the TO TV cable from the SD Sat receiver to theat spot. NOw with the switch off SAT TV will go to both TV's. SD only of course but its an SD receiver.
Home was where I park it. but alas the.
2005 Damon Intruder 377 Alas declared a total loss
after a semi "nicked" it. Still have the radios
Kenwood TS-2000, ICOM ID-5100, ID-51A+2, ID-880 REF030C most times