Good luck with the new coach. Newer rigs use different gear for surround sound, but yours should have a TV setting just like the settings for vcr,dvd, satallite etc. Is your main unit a receiver? Does it bring in am and fm radio? Look for TV setting which should let tv audio play thru surround system. On some systems you can lower volume on tv set and just use surround speakers, you have to experiment if the manual does'nt cover this.
hope this info helps thanks AJBJRVERS