[Rebel702]

With my new 3811MS - Furrion TV and IR32 DVD/Stereo
Used a headphone jack to RCA line. Just above the side HDMI connections is the speaker out jack. You have to remove the DVD player to access the back RCA inputs (bottom row, white and red.)
When you connect that line the TV will show external speakers - Variable or Fixed sound. Choose Fixed. The stereo should then be set to TV Speakers. You have to use the remote for the stereo to control volume and mute.
Check Best Buy or Walmart or Amazon for the cable. Buy the cheapest. Probably less than $8. My is 4 ft long to fish down to reach the stereo.