I have a Keystone Sprinter that has both cable and satellite hook up outside. When I tried hooking my Direct Tv dish to the out side connection and then connect the receiver inside, it would not work. Like you. if I connect dish to receiver directly it worked fine. I then using a ohm meter, checked the cable that runs thru the trailer. It had a direct short. Somewhere during construction the cable was damaged. I checked the cable as best I could with no luck. My dealer was 1500 miles away and Keystone dealers here, either would not work on it or said it would be months before repairs could be made. ( that's the problem with buying over the internet). I bought a exterior cable cover and drilled thru the side of the trailer, sealed it good and ran a new cable behind fireplace and up to Satellite box.
