I have a 2014 Winnebago Sightseer. In the compartment above the driver side is the connections for satellite hookup. I have a DISH Wally receiver in which the HCMI cable goes into the wall and then c...
Pulling that new cable through will be tough, as it probably makes several sharp bends and has a connector on the end. And if the joint between old and new comes apart while pulling, you're done-for.
Perhaps worth a try, though, as your only other choices are to snake a new wire route, or run a surface mount.