You might be able to fish a coax cable through the shore power mouse hole or shore power cable access door and install an inside wall jack.
My first TT didn't have any coax connections or cable. It had a small outside door for the shore power cord. I reached through with a drill driver and drilled a hole through an inside wall in the compartment and pushed the end of a piece of RG6 cable through the hole. I added water proof end connectors. I have a spool of RG6 and make my own cables.
I left enough cable with a coupling on the end coiled inside the compartment that I could pull out to connect to a longer cable to hook up my sat dish.
