Defrost/Fogging Front Windshield issue

[NYerinSoCA]

Have issue on 2005 S60 that can not figure out why it occurs, but front windshield always fogs up and constantly have to run AC on it to clear it, and living in Southern California where the temp goes lowest is 50F, and hardly ever rains not sure where this moisture is coming from that would make me have to run AC. Happens almost every time sun goes down and windows are closed. But rather not run AC at night when in reality might need to run heater but can never do this especially with setting on front window position. This occurs wether have circulation on or not, and only is the front window inside and no others ones fog up at all. Have tried RAINX for interior fog formula they have but very little improvement. Any suggestions how to minimize this issue, or solve it would be helpful.
Oh yes I do have one spot on windshield that was hit with stone that had place fill in so wouldn't cause crack, but this occurred shortly after go car and do not recall if occurred before this or not, has been two years now since was filled in and has not expanded.

[Marmitespreader]

Hi
Is there any wetness in the footwell carpet area, have you checked the coolant for leaks, a/c not vent pipes blocked?
For now until issue resolved, you could leave a bowl of salt in the car, perhaps leave a window open a centimetre & do not use ac for a while.

[NYerinSoCA]

No leaks at all inside, and AC dont believe blocked cause works great. have left window opened a crack while driving at night time and have to open it like 1/2 way down to not have fog up. Coolant level has always been fine. Just seems someone turned a humidifier on inside front windshield. Temps at night are 60'sF right now, and there is very low humidity in air here

[Chris_Rogers]

Sounds like the AC condensate drain pipe is blocked leaving the water in the car.

[Clan]

Originally Posted by NYerinSoCA

Have issue on 2005 S60 that can not figure out why it occurs, but front windshield always fogs up and constantly have to run AC on it to clear it, and living in Southern California where the temp goes lowest is 50F, and hardly ever rains not sure where this moisture is coming from that would make me have to run AC. Happens almost every time sun goes down and windows are closed. But rather not run AC at night when in reality might need to run heater but can never do this especially with setting on front window position. This occurs wether have circulation on or not, and only is the front window inside and no others ones fog up at all. Have tried RAINX for interior fog formula they have but very little improvement. Any suggestions how to minimize this issue, or solve it would be helpful.
Oh yes I do have one spot on windshield that was hit with stone that had place fill in so wouldn't cause crack, but this occurred shortly after go car and do not recall if occurred before this or not, has been two years now since was filled in and has not expanded.

Perhaps the recirculation flaps on the heater are broken , there are TWO flaps which have to work properly , the mechanism is on the outside of the heater unit on the end on the passener side .

OR The pollen filter is blocked ,

OR THE AC drain is blocked , you should have quite a lot of pure water dripping out on the floor under the car when the engine is running and AC on .

[Brendan W]

Originally Posted by NYerinSoCA

Just seems someone turned a humidifier on inside front windshield.

If the condensate drain is blocked that's pretty much exactly how the system will behave.

[NYerinSoCA]

THANKS, I will attempt to look into these suggestions, and start with drain pipe Appreciate the help first time posting and first time owning Volvo..

[sneakypenguin]

I had this happen in my previous car (vauxhall omega). Turned out that the scuttle drain on the passenger side was completly blocked, had about 5inches of water and debris inside, as that was where the pollen fileter was located is was utterly soddon.

As has been said above, check the pollen filter and ac drains.

mick

[Haylands]

Originally Posted by NYerinSoCA

Happens almost every time sun goes down and windows are closed. But rather not run AC at night when in reality might need to run heater but can never do this especially with setting on front window position.

I concur about the blocked drain but just reading the above, do you realise you can run the AC in hot mode?? personally I leave mine on all the time hot or cold rain or shine and it dehumidifies blowing hot or cold air...

[RM955I]

Leaving it on also stops the seals from drying out and keeps them lubricated, helping to keep the system in good condition