Help with moldy AC smell
 

Does anyone have a good long term solution for this dreaded problem? I don't normally turn on the AC, maybe sometimes in the summer and when I am defrosting/defoggig in the colder weather. But when I do, when the AC is off, the moldy smell starts. When the AC is running there is no moldy smell.

What can I do about it? I have tried to spray some lysol from the AC intake area from the engine bay that that didn't do much.

Anyone want to share his/her experience with this common problem? Thanks.

Have you replaced the cabin filter? I leave my AC on 100% of the time and just adjust the temp as needed ... warmer or cooler.

No I haven't replaced the cabin filter yet. If it was the filter I wonder why the smell would change by turning on and off the AC.

It's a good idea to leave the a/c on auto full time as it helps to reduce humidity year round in the interior including the vent duct work. If the a/c was only used sporadically, there could be some mold from moisture that developed in the climate control system somewhere. When you turn the A/C on, it is likely filtering the smell from the cabin until it's turned off again.

Start with the easiest possible solution by replacing of the cabin filter and cross your fingers. It should be replaced every couple of years or 35K miles depending on how much city traffic driving you do.