Our 2003 Jayco has what I'll call the "basic" TV setup:
Winegard connection Plate with Booster Switch (12V supplied to Plate from Coach)
Winegard crank-up Antenna connected to the back of the Plate
External "RV Park Cable" connected to the back of the Plate, to outside of coach
One TV connected to the front of the Plate
Second TV connected to the back of the Plate
If that's what you have, all you should have to do:
To watch Antenna TV is crank antenna up, turn Booster ON, rotate Antenna for best reception.
To watch Cable TV, connect your outside cable and be sure the Booster is OFF.
Our coach had its connections changed by the previous owners. They wanted to watch TV from an additional source and all it took me to restore to original design (above) was rearrange the connections on the back of the Winegard Plate.
Winegard plate wiring diagram is available on-line. If your setup is different, let us know. Some are a good deal more complex. I helped with a Winnie on Sprinter (2007 or so?) that had all the above plus DVD player and pre-wired for a Dome. There was a switch or two. It'd been miswired by a "professional" who charged a couple hours labor and left it with nothing working. Luckily it was Winnebago, so we could look up the wiring diagrams. Once we got it back to OEM, it all worked. The problem was that their OEM TV was flat screen but did NOT have a digital tuner. They were carrying a digital flat screen and rabbit ears around in a plastic bag to set up and try to find signal. Hooked it up to the corrected wiring and made them an adapter to put new TV on old mounting. They were the picture of Happy Campers!