Odor from vents

[Fossil]

I have a 2012 Ram 1500 I bought used nearly 2 years ago. Only had 35,000 miles, love at first sight.
This winter, whenever I use the defroster to clear the windshield an odor is emitted that I thought to be a AC refrigerant leak. Took it to the dealer and they said there is no smell to AC refrigerant.
I did turn on the AC to see if the same smell was present but didn't notice anything.
I do use a commercial car wash and wondered if the high pressure air after the rinse may have forced soap or wax someplace where is shouldn't go.
Any ideas?​

 

[Jrod]

I had a Neon back in the 90's that did this exact same thing. In short, water was collecting and mildewing in the outside vents. All I could do was run the defroster and spray Lysol into the vent under the wipers to kill the mildew. I would then have to leave the windows open and let the car air out all day...

 

[RamInfo]

Had a similar issue on my Dakota, due to a plugged drain condensate from running the AC was collecting and mildewing. Cleared the drain and started turning off AC but leaving fan run when I turned into my subdivision and the smell went away.
Best,
DG

 

[Fossil]

Thanks for the reply's. I'll be checking the drain tube as soon as I find it.

 

[DailyRAM driver]

I bought some cleaner for the evap coil off Amazon that fixed this. It's due to milldew on the coil and duct. I think the stuff is call Kool-it. You feed a tiny hose from the can into the condensate drain through the firewall. I do it once a year, cost about 10 dollars

 

[Fitz-0518]

That's it. Had the same smell in our 07 and 03. Ran a can of coil cleaner in the box. Smells like new. My AC guy gave me a tip that is working. If you use a drive thru car wash. Turn the AC off. Set the the vent open "outside" air and turn the fan on. When you go thru the high pressure dry fan, the fan will force some air down thru the outside windshield intake and out the condensor tube.

 

[Fitz-0518]

Passenger side firewall at the bottom of your heater box.