Welcome to JOF swaggerstick. Everything’s subject to the prior owner swapping out the original for better stuff. In our 2014 Eagle, the radio and Tv we’re independent but TV sound could be routed thru the stereo with the push of a few buttons. Are there separate remotes? I’d start with the TV on and stereo off - sound should come thu the tv speakers. Once the TVs up n running, turn on the stereo and try tunning a radio station. Once you know the radio side works, press the aux button until tv sound comes thru speakers. Full disclosure, I can’t remember what the stereo looked like on the Eagle.
2019 Pinnacle 36 FBTS
2016 Silverado 3500 CC SRW DuraMax/Allison
1975 Corvette for the sunny days n dry roads
2017 RZR for the rainy days n muddy roads