All of the 'golfball' sat dishes get their operating power thru the coax cable and must have a direct connection between the dish and the receiver box.
Most likely you have some in-line switches in your coach's interior coax. This is probably your problem.
One solution is to just run new coax line in your coach directly to the box.
I believe there are ways to rework the switches if you can get at them.
Hopefully someone also will chime in here.
I have a Winegard X2 and have the same problem. This is a common situation.
If you do a search on these forums you will find more discussion about this problem.
Tim