On my Jayco Whitehawk, the splitter is inside the entertainment unit. I had to remove the back panel behind the TV to get access to it. They stapled and glued the panel on so I had some trouble getting it off. Since there are serviceable parts inside, including the splitter, I used screws to put the panel back on as they should have in the first place. Now I have easier access to it.
This is where you should look for your splitter. It will probably be in close proximity to the TV.