Hello,

Car was bought last summer so I did not run into this problem until this winter. What happens is that all of my windows, including the front windshield are always fogged. It does not matter if I run A/C at 60c or 70c, turn off re-circulation, or hit the Front window button, it stays foggy. I can try and wipe down the windows with a cloth but it does not clear up the windows. I have not dropped my car off at the dealer for a diagnostic but google search lead me to believe I might have a leaking heater core. This repair costs 1k+ because they will have to remove the whole dash. Something I am not looking forward to

 

Did the A/C and other cabin air controls work as expected before the winter?

When you turn on the front defogger, does air come out the vent at the base of the windshield? Can you get basic heat from the vents right now? Do you smell anything unusual if the heat is on?

Btw, recirculating the air is probably going to make fogging worse.

 

A/C and controls works as expected. I still get heat and A/C. When I turn on front defogger, air does come out at the base of the windshield. No unusual smell if the heat is on and no signs of leak under the passenger or driver's side carpet.

 

hmmm... do you know that fresh and recirculate are both still working? IOW, you know you can switch from one to the other?

 

Yes, both are still working as expected.

 

I'm not trying to be difficult. But how do you know there's a difference between fresh and recirculate?

 

If your carpet somehow got wet, it will fog your windscreen. You can hire or buy a dehumidifier, and let it run all night when the car is under cover. This will help dry out the felt UNDER the carpet, even if the carpet feels dry.

Try to eliminate all obvious things first like a blocked aircon drain hose or wet carpet from a window being left open overnight, before spending big.

Hope this helps.

 

Have you checked the sunroof drain "boxes" at each front corner inside the kick panels? Check to see if your sunroof is draining by pouring water, slowly, through the sunroof tracks and see if it's draining from underneath - should be closer to the B pillar (between the doors). If no water is coming out, you have water trapped inside the drain boxes. It'll take some digging to find the threads talking about how to clean them out. I don't know who thought up the brilliant idea of not having sunroof drains actually drain directly outside of a vehicle.

If water is trapped inside those boxes, they will contribute greatly to excess moisture inside the cabin.