Don't install 12v TV...too expensive and better way to go is inverter to run TV. There are many posts about TV on here, need to do some rerading to make inofrmed decision. Some TV come with external power packs which makes them 12v or 120v. Plus do you have an antenna/dish or ? Also, the concensus I have drawn on RVNET is that the Jensen set up isn't that great...again make wise informed decisions, do many searches and read the theards. Use the TC Univesity section, explore and read...much of what you are doing is covered, mentioned or completely sorted out.
Now with some of the posts you have going already...you should tell us what you are actually doing...like the rotten section you found...it seems to me that needs to be done and then these other things. am glad you have taken this on, because your expereinces in doing the porjects will add to the total knowledge base, if you contribute the solutions in the threads with pics,naturally! Good Luck! Again JMHO!!!