I just bought a newer motor home and again the tv isn't hooked up. There is twelve cables in upper cabinet and none marked. Roof satellite . Distributor box for front ,back And out side tv's. Extern...
In my experience over my lifetime, I have found that if you are that lost, you need someone physically there to help or do it for you.
Kinda like programming the old VCR clock. Some people can do it in a few seconds, and others will only frustrate themselves trying.....doomed to staring at the flashing 12:00 :)