defroster smells like hot garbage

Subject says it all.
2013/2.7/AC/42k mi

It stinks moreso if I have it dialed towards heat. On settings other than defrost I haven't noticed it - that includes heat, ac, recirc or fresh. The cabin filter is less than 5k miles old. I'll pull it anyway to have a look. I can also confirm that the water drain for the air conditioning is not blocked. I noticed the smell for the first time this week and coincidentally that coincides with my first morning defroster use.

I've heard that our Tacos don't have a screen on the intake side of the system and I fear something sinister has happened like mouse massacre inside the system but then I imagine it would stink always, regardless of setting.

Any thoughts? Could this just be mustyness from lack of defroster use? Any ideas on what to try. I'll mention that I'm particularly sensitive to odors - whether it be perfume or trash. What other don't detect or don't find offensive tend to bother me much. So maybe I'm making this out more than I should but there is definitely SOME kind of funky odor.

 

Mouse nest on top of cabin filter

 

I’d check the cabin air filter and maybe even pull the fan out and shine a light up inside to see what’s going on. On a weirder note: one of my biggest fears is someone barfing in my defroster vents. In case you were wondering

 

You too?

 

Doesn't the AC come on when in Defrost mode, even though the AC light is off?

Drive with the AC on and you'll probably notice the same smell.

In my experience the smell goes away after using AC constantly.

 

Cabin filter is the first place I would look.
Then some fabrezz!
It's behind the glove box

 

Will def be checking there cabin filter. Yes, ac comp should cycle when defroster is in use. However, with ac blowing through front vents - no smell. Only on defrost.

 

https://www.tacomaworld.com/threads/mouse-in-cabin-air-filter.292806/

Some people in this thread have put a screen over the air intake.

 

So it doesn't matter if it's heat ,AC or just air it only smells when coming through the top vents up next to the windshield correct.
Not any other setting?

 

https://www.youtube.com/watch?v=GkN4bwyY3jM

 

Someone parked in my cousin's parking spot so he ended up taking a piss in a bucket and pouring it down the vents of the culprit's car.

 

Sweet baby Jesus

 

.

 

WTF.

 

Lol

 

I would have to hurt that MFer .