Hi fiverdude,
First of all, congratulations on your new Big Country and welcome to the Heartland Owners Forum. There's lots of great information here along with a great bunch of friendly and helpful people.
Satellite signals won't usually pass through cable splitters and definitely won't get through the signal booster that's on the cable TV hookup line.
If you're running both cables through the window now, I'm guessing that you're having trouble with getting the existing satellite line to the entertainment center to work, and you need a 2nd line. Let's talk about the existing line first. Here's a link to the
BC COAX layout in the TOOLS/HOM OWNERS MANUAL section of the forum. If I have the correct diagram, you have 4 satellite connectors in the UDC. 2 go to pre-wiring in the roof for a rooftop dish. The other two go to the living room and bedroom. If you've tried the one marked Living Room and it doesn't work, you should try each of the others. The factory could have gotten the wires or labels swapped. If you leave one cable going through the window, you should be able to tell when you hit the live connection. It's also possible the label in the living room could be wrong.
Another possible problem is a bad crimp on one of the connectors. Check for loose connectors and for shield wires touching the center conductor. If you don't feel like dealing with this, you might wait until you take the rig in for service and have the dealer fix the coax connections.
To get the 2nd line, you have several options. It's clumsy, but
flat COAX cables are widely available now. They are intended to go through windows. A 2nd choice is to add additional cable, running from the UDC, down to the frame, and back to your entertainment center.
A 3rd, and probably the best choice is to change your receiver and LNB to Single Wire Module (SWM). Your receiver may be enabled for SWM (you can check the menu on dish types to find out). A Directv servicer/installer might be willing to give you a SWM LNB upgrade to replace your existing multiswitch LNB, or you can
buy a kit on Ebay. You need the LNB, a power supply, and a SWM splitter. SWM requires only 1 wire to the receiver, which then acts like the old 2 wire arrangement. Both tuners work from the single wire. Of course if your receiver isn't SWM capable, you'd have to get a new receiver to do this. If you've been a customer for a while, Directv might even give you new equipment.
Good luck.