Windows won't un-fog

[bnther36]

I'm just curious to see if anyone else is having window fogging issues. I've never had so much trouble with this on my other cars, but the little Yaris just does NOT want to cooperate.

[ChinoCharles]

Turn your AC compressor on along with your defroster. The problem is with removing the humidity from the air in your vehicle, which your AC system will do.

[Chupacabra]

and have it on recirculate mode, correct?

[SailDesign]

OK - you two need a time-out. Sorry, Chino, but....
1. The AC automatically turns on "when needed" with the defrost aimed at the windscreen. Nothing you can do to stop it - I've tried.
2. Recirculate will not get rid of fog - stick it on "fresh air".
3. Flame on! (probably)

[Revsson]

I agree with #1 and #2 above.

[ChinoCharles]

... I'm driving down the road. Its cold out. My windows are fogged up. I crank the defroster on high. Nothing. I hit the A/C button and within about 5 seconds my windshield is clear.

That happens, oh, every day during the winter.

[SailDesign]

... I'm driving down the road. Its cold out. My windows are fogged up. I crank the defroster on high. Nothing. I hit the A/C button and within about 5 seconds my windshield is clear.

That happens, oh, every day during the winter.

Dang! Want to trade? I cannot turn off the AC when defrosting. Says in the handbook that's what it does, IIRC.... Strange.

[voodoo22]

When my windows fog, and I turn it to defrost, the A/C goes on automatically as well. That's how most newer cars are from my experience.

[KCALB SIRAY]

Fog-X works pretty good and also using shving cream on the window and wipe it off...don't knock it until you try it

[steved]

... I'm driving down the road. Its cold out. My windows are fogged up. I crank the defroster on high. Nothing. I hit the A/C button and within about 5 seconds my windshield is clear.

That happens, oh, every day during the winter.

Get your system checked. When my windows are fog up I put it on defrost and it clears up right away.

[SilverBack]

Turn on the A/C, fan, and defroster. Turn the knob to "defrost" setting. If that doesn't work, then crack the windows a little to let some of the humidity out. Never fails.

[SailDesign]

Well, I stand corrected (although I'm sitting down)
Following is from the '07 Owners Manual, showing that you DO need to push the button. Dunno where I (mis)understood that it was turned on automatically.....

[darthbauer]

I just put it to fresh air and click it on to 4 and all the way to heat and the fog goes away in less than a minute.

[WeeYari]

Well, I stand corrected (although I'm sitting down)
Following is from the '07 Owners Manual, showing that you DO need to push the button. Dunno where I (mis)understood that it was turned on automatically.....

We used to have a thread or two which debated whether or not the A/C compressor came on automatically in the Defrost setting. Topic I think came up during fuel economy discussions. Still don't know if any definitive answer surfaced.

My personal experience is the defrost setting will clear the window in seconds with no need to push the A/C button.

[Bob_VT]

Check to see that the body plugs are in place and not allowing more moisture in..... feel your carpets to see if they are wet too.

[bnther36]

Here's some pics of my windows after 45 minutes of driving with the defroster set to recirculate, medium heat, and #4. I tried switching to regular heat, instead of defroster and within 60 seconds the windshield started fogging up. And it's THICK when it does fog up.
I've never had a car do this before.
12455

12456

[BailOut]

I commute over a mountain that sees over 300 inches of precipitation per year and I have never used the a/c or defrost setting. When the windows fog all I do is crack the window and in a few seconds the windshield is clear.

[SailDesign]

Here's some pics of my windows after 45 minutes of driving with the defroster set to recirculate, medium heat, and #4. I tried switching to regular heat, instead of defroster and within 60 seconds the windshield started fogging up. And it's THICK when it does fog up.
I've never had a car do this before.


It's the "recirculate" that is killing you there. Been there, done that, noticed the problem - all fixed!

[dybbuk]

I know my '08 turns something on when I set it to defrost, I can hear something kick on. Anyways, what SD said, turn off recirculate, you need fresh air. I get heavy frost in mornings here, and while I haven't had winter conditions yet, I sure haven't had any problems defogging the frost.

[Callisto]

+1 on opening the vents. You are putting a LOT of water into the air just by being in the car while you perspire and breath. Human beings have one of the best natural temperature regulation systems on earth, but it burns through a LOT of water. If you have water in the air on the inside, raising the relative humidity, and the temp of the outside glass is below the dew point of the air inside, bingo, you get "fog." Simply, you are putting more water into the air than the cold air next to the windows can handle, so it condenses into liquid water on your glass. Bringing in air from outside equalizes the relative humidity with the great outdoors.

[stran]

i know my A/C turns on in the defogger mode. i started a thread on trying to unlink the A/C from the defroster in the DIY forum, in case you're interested.

[Reddog99]

What's that white stuff all over the car in that photo?

[Revsson]

We had some snow flurries and icy roads in Wisconsin this evening. There was
something like 27 accidents in an hour during rush hour. I guess winter is here....:eek:

[floydisrock]

you need to use fresh air mode when defrosting the windows,not recirculate.

[voodoo22]

you need to use fresh air mode when defrosting the windows,not recirculate.

+1

[ToddR]

What's that white stuff all over the car in that photo?

I think it's called "ash" in SoCal.

[bnther36]

Well, I tried the 'fresh' air as opposed to recirculate and guess what...NO FOG!

My thanks to all that helped. Ice is bad enough, but icey roads and foggy windows makes for a really nerve wracking ride.

[sportin83]

i agree with this i have never had this much problem with fogging till this car.

[dybbuk]

Agree with what? He solved his problem. What's yours? :P

[09TRD]

i agree with this i have never had this much problem with fogging till this car.

You have to select the fresh air setting in order for the defogger to work correctly.

The little diagrams on the car's ventilation switch make that perfectly clear, as does the owner's manual and good sense.

The defogger in my '09 Yaris works at least as well as any of the other 15 or so cars that I've owned.

[white_rice]

Hey guys.. know this is an old thread but bringin it back to life. The inside of my windows have been fogging up bad as of the past few weeks on my daily commute to work. I have it set to 'fresh air', not 'recirculate'. Temp is on the warmest setting, vents are all open and directed to the side windows, and fan is on high. Even after driving for almost 30 minutes, its my rear side windows that are fogging up terribly. To the point where I can't see out of them whatsoever. Not sure what the problem is here but maybe I need to to try this turning of the AC on manually as this is the one thing I just read here I have not tried.

[white_rice]

The past couple weeks every day driving the vehicle, the rear side windows have been fogged up beyond belief. To the point where I have to put the windows down to reverse into a parking spot.

Have tried everything from ensuring the switch is set to fresh air, direct the air vents towards the side windows, push the AC button on, and even crack all the windows slightly.

Long story short I may have found the problem today. Emptied out he entire hatch including the spare tire, to find a huge puddle of water frozen in the centre lowest section of the hatch (under the spare tire). There was also some water on the floor surface area by the drivers side tail lamp.

Dried everything up and ensured the black rubber grommet was in place on the hatch floor. Not sure at this point how all the water is getting into the hatch but I do believe this explains the window fogging.

Will keep posted.