Mist On Out Side Of Windscreen

[Malaka2]

My toyota mark ii front windscreen become mist in rain nights and become very unstable to drive when light beam hit on the screen on night.. The mist is comes from outside of the screen and not wipe out from wippers. Please tell me what should I do? Its impossible to drive at night in these days..

[harshansenadhir]

  Malaka2 said:

My toyota mark ii front windscreen become mist in rain nights and become very unstable to drive when light beam hit on the screen on night.. The mist is comes from outside of the screen and not wipe out from wippers. Please tell me what should I do? Its impossible to drive at night in these days..

mist or condensation due to a/c ? If it's mist and doesn't wipe off, check the wiper blades first. If it's frosting or condensation, you will have to look at the cooler box to see whether is there faulty leaks into the defroster lines.

[Malaka2]

It's not cause by A/C. Is there any liquid to clean the windscreen from out? Because what ever it is its appears from outside.. Its like a mist. But not even wipe out when wiping from a cloth..

[SeanD]

If you're insisting that the windscreen is not misting up from the inside, then the only thing I can think of is that there is some sort of small fracture in your laminated glass that is causing the windscreen to mist up WITHIN itself. I have never heard of this happening though, unless your car has had it's windscreen replaced with some sort of sub standard screen some time in the past.

Are you sure it's not just condensation on the INside of the windscreen? That's fairly common in colder countries, or in SL if the inside of the car is heated and it is raining/cold outside. It's pretty much the same as a glass of cold water, and whichever side has the warmer air will see the mist forming.

Even if it's somehow misting inbetween the sheets, the only suggestion I can think of is the standard way to get rid of mist on the inside:

Turn your AC up to it's full cold setting, and switch it to the Windscreen Demist output (the orange windscreen with waves sign that is usually on the extreme right of your A/C vent settings). Let it blow for a while, and once the windscreen is chilled enough the mist should disappear, regardless of which of the two above scenarios is causing your problem. A common method of preventing this happening again in cold countries is to take a spot of shampoo and rub it on the glass with your finger (inside). Then wipe it clean with a cloth. This will prevent condensation on the inside.

The best way to check whether there's actually something wrong with the laminate is to go home, turn the car AC off, park it in a warm place/garage, and take a hairdryer and hold it over that spot from inside or outside. If the problem goes away, you'll know you have a potentially serious flaw in your windscreen.

Sorry if you have already tried the above, but thought I'll provide some general info. I'm always surprised by how many people on the road on rainy days don't know the purpose of the windscreen demist setting on the A/C, and are seen stopping the car on the side and frantically wiping the inside with a cloth, or trying to wipe it while driving.

Edited December 29, 2009 by SeanD

[fatjoe]

Sean bro,

Dats some damn good tips. About this demist setting , I tot its only for rear Windscreen. Coz U get dose metal lines in da rear windsheild.

[SeanD]

  fatjoe said:

Sean bro,

Dats some damn good tips. About this demist setting , I tot its only for rear Windscreen. Coz U get dose metal lines in da rear windsheild.

Just to clarify any doubts that may arise:

This button on your dash is for the rear window:

That is why it's a rectangle, and operates the heating lines running through the back windscreen. Rather than the method of blowing cold air, as is done on the front windscreen, this actually heats up the glass so that the temperature is closer to the same on both sides and makes misting less able to happen.

This button/setting on your A/C, is for the front windscreen, and the front windows as well.

Hence it's shape is the same as that used on the windscreen wiper switch. You will need to adjust the temperature (either all the way cold, or all the way hot, to match the outside temperature) and turn the blower up to full. On some car models that use push buttons instead of a physical knob to control the blower, this may happen automatically.

[Tikiri]

This mist can become a nightmare if its raining, specially at nioght.

This could also due to the Air con doors to the windscreen deteriorating, generally they use a sponge type of a material and with time it decays. So it will be worthwhile to show a good AC workshop and they will re do the thing,

[ruwds]

another observation is that if you have cold air from the A/C blowing to the windscreen through the demist vents for quite some time, a mist can be formed on the outside of the windscreen. This could happen even when the vent settings are normal (blowing into the car through the top or/and lower vents) AND there is a small amount of air getting leaked out from the vents under the windscreen.

[SpEeD FrEak]

  ruwds said:

another observation is that if you have cold air from the A/C blowing to the windscreen through the demist vents for quite some time, a mist can be formed on the outside of the windscreen. This could happen even when the vent settings are normal (blowing into the car through the top or/and lower vents) AND there is a small amount of air getting leaked out from the vents under the windscreen.

yeah.Once our car had a similar problem.If the control is faulty some times when u put to demist and again turn to the normal mode cool air will blow from demist vents.