I never had any luck using the SAT outside connection on my trailers. What I did a few years back was to run a RG CABLE from each of the two ports on my portable SAT DISH to a SAT RCVR I brought from home near the TV located in the main room and also in the bedroom.
Then I hooked up the RG cable to the SAT RCVRs in each of the two rooms. Then I ran VIDEO CABLES from the SAT RCVR to the VIDEO INPUT CHANNELS on those TVs.
Now I can watch SAT TV or CABLE/OTA TV by using the TV REMOTE.
I could have rewired the SAT CABLE you are referring to but didn't want to mess with changing things. The problem is this SAT CABLE is tied into a SPLITTER where the CABLE TV is also using and you can't separate them to be used at the same time. The splitter also kills the SAT DISH DC control voltage going to the SAT DISH head.
I was able to get my RG cables from the pass thru storage area to the two rooms inside the trailer and just left the two cables coiled up laying on the floor in the pass thru storage area. Then I can hook up to my portable SAT DISH when we setup at the camp ground.
This is how I got my setup to work back then. The newer DISH ANTENNAS are probably a bit different now but this is the main reason you can't use the SAT CABLE on the side of the trailer.
We have been leaving our SAT STUFF at home now since the NATL BROADCAST TV signals changed over to digital TV. We pick up these signals using our OTA Batwing antenna and they are all in full blown high def digital HDTV mode. We usually get 6-36 digital channels from the local towns just about every where we go here on the East side of the US. And it is all FREE to the public to use...
Maybe others on here will have a better work-around
Roy Ken