XSV

iTrader: (1)

I clean the inside of my windshield and and window glasses. No streaks/smudges. Then as the days go on, I start noticing smudge streaks all on the inside of the windshield on the passenger side and on the inside of the passenger window. I tried looking up what the cause may be and all I found were heater core leak or plastic outgassing. I recently had my dash replaced, but this was occurring before the dash was replaced. As for the heater core, I haven't had any problems with the heater in the winters and no weird smells. Non-smoker, and I'm sure it's not from someone touching the glass. I run the car with cabin air filtering, not outside air. Anyone has had this problem? It's really annoying.

MikeFig82

iTrader: (13)

I get the same thing once in awhile. I actually have to wipe down my window again, because it's fogged up again. My theory is that the moisture is coming up once the A/C is turned off. The moisture is venting out through the defrost front section which runs along the dash near the bottom of the windshield. I always leave my A/C on recirculating mode.

Bichon

Is this happening all the time, or just in rainy/cooler weather?

Running with the vent set to recirculate all the time is likely part of the problem, and the humidity you see may be coming from your breath and from condensate on the evaporator core re-evaporating.

The recirculate setting is great for cooling the cabin down quickly on those blistering hot Texas days. But at other times when the heat load on the HVAC is lower, the evaporator coil may not be cold enough to dry the air, causing the excess moisture to condense on the windows. Try using the auto or ventilate setting -- I suspect it will eliminate the problem.

XSV

iTrader: (1)

Happens all the time regardless of rain.

Gville350

iTrader: (10)

It's the humidity that does it on mine here in SC.

primavera

If it's not heater core then I bet it's clogged up A/C drain.
https://www.clublexus.com/forums/gs-...-ac-drain.html