It been cold and plenty of snow around Boston this winter.
Often , not everyday, My windows are fogged front side and rear.
I found that the sunroof wasn't fully engaged, maybe I bumped the button when
going for the TRAX at night? But that didn't solve it.

There was some snow tracked into the floor mats.
Maybe that was the culprit? This AM the windows were OK.

I don't think it's anything to do with the heater core because there's no stink of antifreeze.

Any ideas?

Puzzled, Bill

When the defrost is on the AC is also turned on. If the condenser drain is plugged there may be water collecting in the HVAC unit.

Thanks Fixit!

Everythings's been OK for a week, since we have had an interlude in our series of snowstorms here (Boston). How do I check that drain? Where exactly is it?
Maybe that's what's wrong here.

Bill

If the heater was on recirculate for an extended period of time and there is a high humidity situation in the car (snow will do it) fogging will occur. Have you had the car full of people recently (exhaling humid air)? Drinking lots of hot coffee in the car contributes heavily to high humidity.

Driving 20 minutes or so with the heater on fresh air will clear things up, unless there are other issues here that are adding humidity to your car, like a heater core, or a leak into your passenger compartment.