I know this has been dead for a couple years, but it seems to be the only reference on this forum to accessing the main salon AC. I may have the same issue as BellaDonna, my AC compressor is running, but no air is blowing from the vents. I assumed it was a fan motor, but if a joint for the duct was just taped, that could very well be the issue.
The question has not really been answered though, obviously in BD's situation access had to be made to repair the duct (kudos to whoever had the balls to diagnose the issue with enough confidence to start cutting holes in walls, and the knowledge to know where to cut the access), but how can you access the compressor under the floor? Is there an access in the floor there?