From what I've seen, WRV upgrades video components frequently. That -- coupled with the use of the Winegard switch and their quest to provide better video quality -- makes for a lot of potential complexity.
I have not seen an 06 cabling diagram (you should have one in your manual), but, I'd guess the connection between your 942 (which is Sat, not cable BTW) and TV is not routed through the Winegard (I'm not aware of Winegards that switch component video or other HD signals, only coaxial/cable and conversion of composite/yellow-RCA jack to coaxial).
If so, I'd check the TV menu to verify that the right input has been selected (probably to an "HD" or "analog HD" setting.
If you then try to receive "cable" from a park connection, that same TV input will need "re-selecting" to a "cable" setting. And, you will need to select CABLE on your Winegard.
If you want ANT reception on either TV, you need to selct ANT on the Winegard as an input and then ANT for each of the TVs, also on the Winegard.
If this works for the BR TV and not the MAIN TV (and/or the MAIN TV gets no CABLE,but does get SAT), it likely means the MAIN TV has been connected with through its component video connection, but not through a coaxial (cable type) connection.
First try the menu button for the TV to see which input is selected.
Sorry if this seems confusing. One option is to employ a home theatre-type tech for a few hours(prevalent due to this very confusion with emerging hi-def signal connection).
Or... experiment and post back
2004 Alpine 34 FDDS
Anaheim Hills, CA