Randy, Hello and welcome to iRV2, Sounds like you do in fact have ducted roof air system and that some where there is a problem near the A/C unit that is blocking the air flow. Is there any sign that the unit has been repaired or replaced ? Or do you have any vents from the A/C grill on the ceiling that are moving air? First thing to do would be to drop the return air filter down and make sure someone has not pluged the return to stop cold drafts in winter. Then turn the unit on to see if it is drawing any air. Note some units run the compressor for 1>2 mins before the fan cuts in so that the air is cool as soon as the fan blows. Good luck.
99DSDP 3884, Freightliner, XC, CAT 3126B, 300 HP /ALLISON 3060
2000 Caravan toad, Remco & Blue Ox.