Hi AAdams,
Have you verified that the dish, the receiver and the TV are working correctly before trying to use the RV's wiring? Run the coax from dish to receiver first and make sure everything works. Then connect the dish and the receiver using the satellite coax connectors in the RV. The cable TV connector sends the signal through the antenna signal booster which interferes with satellite frequencies.
If you've done all that, the most likely problems are 1) incorrect labeling of the connectors, and 2) a loose or shorted coax connector. If you're plugged into the satellite cabling for the RV, the splitters and barrel connectors could be loose, but are not likely to be the wrong type of connector.