Watch these videos and then address your AC units. Your RV has been on the road for 5 years now and chances are just needs a little attention, an easy fix. All the movement over the years results in AC unit seals that are no longer doing their job as good as should be. Properly seal those vents for the most efficient use of your AC units. You would be surprised what a difference it will make based upon escaping cool air being sucked right back into the intake and not cooling the RV.
Coleman or Dometic roof AC not cooling properly. Check, test and fixAll Seasons Mobile RV Repair. RV AC not cooling properly