Funny Smell

My 00 yukon when i turn on defrost has a musty closet smell. I believe the vents were doing it to at start of winter. I did change cabin air filters but that defrost still stinks. I dont run defrost very often trying for mileage. Is there a spray or some kinda foam to spray into air ducts?

I'm not sure of a home remedy but there is a Technical Bulletin from GM on this. The dealer can clean the system for about $75 and make it smell much better. I believe mold can set up in the condenser causing bad smells throughout the ventilation.

I aggree with YukonGMC, but does yours have a cabin air filter. I think the 00s do . Mine is a 03 and the bean counters dropped this nice feature.
Some times you can do this,
Put fan blower on high and set the vent to fresh. Find the air intake for HVAC,,, it's around the wipers, and spray Lysol into HVAC air intake.
I did this on the wife's Quest and it fixed it. What the heck a couple buck for some Lysol, if you have and left you could use it in the reading room to get rid of other smells.
:lol2:
Tim

There is a spray that is called fridge fresh. My local dodge dealer stocks it.

Thank you guys really appreciate it DAVE