You will want to check the wet bay and look to make sure you have two coax connections. One should be for cable and one for SAT. On my Jayco, SAT is on top. That's where you hook the tailgator. On the inside, and this is where it gets tricky since each floorplan is a bit different, find the "main" TV and nearby that TV should be a coax plate with the OTA (Over the Air) Antena booster switch. Wherever that is, you will likely see another plate that says roof Sat with two connections. In this location, look for a single coax cable not attached to anything. I could be behind a false wall, behind those faceplates I mentioned. That will likely be the SAT from the wetbay. You will want to hook that to the Dish receiver inside.
Jayco assumes that the dealer will install most sat setups and even then they will likely use the rooftop connections, so the wet bay connection is buried and you have to find it. What may help is to contact Jayco motorized and ask them for the Sat/cable wiring diagrams. You will need your VIN number. This could help you identify that cable based on the color. I've attached my wiring diagram, but different model and floorplan, so not going to help you, but you can see how they match up locations and wire colors, etc.
Michael & Angela Foret
North Central Florida
2019 Entegra Vision 31V