"mac51"......The interior of your coach has a series of fluorescent lights in the center of the main cabin roof. On my 2005 Diplomat, you could remove the second fluorescent light from the front and see the wires in the roof. They consist of one coaxial cable and two 12 volt leads (+ & -). Mine was under the light just behind the two front seats, so about six feet back from the windshield.
With that said, make sure you know what your new satellite needs for connection. We installed a Winegard Travler, open dish, automatic antenna and it requires a coaxial cable and a command cable, so the prewired cables from Monaco were useless. They're also pinned down at various points, so you can't use the old ones to pull new ones through.
Unless your new satellite uses what Monaco installed, you're better off to just run the cables along the roof and drop them into the entertainment cabinet. Drilling from the entertainment cabinet, up through the roof is the best way to know where to run the cables down from the roof.