We have had a break in the Summer humidity here so I decided to not use the A/C and just run the vent. WOW it smelled like a dungeon! A musty odor. I have smelled this in other peoples cars once a while but now its my problem.
Any experience this? How do you get rid of it. When I tested the system with the A/C back on there was not a smell/odor at all.

Any help or comments are most appreciated.

 

Never had that in my Rover and I maybe only run my A/C once a week here. My wifes Jag however has this problem, not sure how to correct it though

 

It seems like every vehicle we own does this after you turn the a/c off. Ironically the only car that doesn't is the RR. Our Jag has done this since new... Some people are more sensitive to it than others too .

 

Check your cabin filters, and plenum filter.