That's what I did on my 05 and now 08 Dolphin. With the dish connected to the back cable input, you need to find the other end at the front. If you have a switcher, it would be on the cable input terminal. This would need to be connected to the sat receiver dish input terminal. If you have done this already and still no luck, check the rear cable plug assembly. The cable from the front of the RV enters the back of the rear compartment and is connected to a pass thru connector. Moisture may have got into this connector and corroded it. Visually check and replace pass thru threaded connector and/or cable end if required.
Ellen & Greg
08 National Dolphin DL-35Ci, RoadMaster Rear Sway Bar, Rear Trac Bar, Koni Shocks Front,
Workhorse W22, Kelderman Air Ride, Towing 08 Smart Car