As others have written, knowing what year 3400 you have makes a difference as the cabling system changed around Jan. 2010. A post with pictures of the two different wiring plans is at
http://www.montanaowners.com/forums/...ad.php?t=37324
Depending on the antenna (dish) you have along with the type of receiver you are using, you may have challenges. To start, run the RG6 from the antenna to the receiver through the side of the slide (or a window). That will at least get you up and running until you can sort out the internal cabling system.
Let us know the year of the 3400 and more deatil on the antenna/receiver and I bet we can improve the installation.