Ah, I misunderstood. I thought you meant next to the DVD player, not up by the TV. Yeah, the ones up by the TV should be connected to the output from the back of the player.
The one on the front of the player though, should have been an input.
I'd still pull the DVD and see what's connected back there. The wiring was all messed up on my Brother in law's trailer and they had those jacks wired into inputs on the back of his unit instead of outputs. Then they had a cable from those jacks to an input on the TV. So his unit was wired input-input instead of output-input. Beside that, they had an HDMI cable run between the DVD and TV, which did work right, so their messed up wiring was not only wrong, but also redundant.
There's no use crying over spilled milk, unless it's on your keyboard.