[raja748]

Dear Friends,

I have a SWIFT-VXI.Last monday it started raining heavily in the evening.I turned on the wipres and changed AC mode to rainy one.I was horrified to see that the wipers were unable to clean the windscreen.Some foggy/misty layer was formed on the screen from outside and with each movement of wiper it was spread on the entire windshield making it milky/smoky.I was unable to see my right side.Unfortunately I was travelling on Pune-bangalore highway and vehicle lights from other side were making me blind.The vision was somehow clear when I swutched wiper off and when there were dark patch.

I thought that wiper blades had gone and replaced those with BOSCH blades(dealer did not had ordinary one,so fitted pair which is used for BMW and SKODA!!!).But on friday,I had similar horifying experience and so on Saturday I rushed to my MUL dealer workshop,Wonder Cars,Chinchwad.

Fortunately,it was raining and so I was able to show them the problem.I was there for about 5 hours till they checked vehicle thoroughly.After checking AC and wiper settings and all,they said that everything is fine and were unable to detect the cause of the problem.I took the delivery andreturned home.

Current status is thge problem is still there.Something misty/foggy layer is formed on windshield from outside as soon as AC settings are changed to rainy and wipers spready that across the screen making it hazy/smoky/milky for seconds blinding me.

I request you my friend to please guide me as in what may be the problem and if any solution is there.may be if anyone of our members has faced the similar problem...

Please help me...

Regards,

Rajendra

[dadu]

Try warm air instead of Cold air when using the AC.

[bblost]

Use the vent under the windscreen to direct a blast of cold (some prefer it hot) air on the windscreen.
Clean the windscreen using a mild detergent.
in an emergency you can use tobacco from a cigarette for cleaning the windscreen.

[nishantgandhi]

What do you mean by "changed AC mode to rainy one"?

I faced a similar problem (Getz), but I have seen it with all the other cars as well. There is a foggy layer that keeps getting formed on the windscreen from both inside and outside.

To clean it from inside, I direct the air flow to the windscreen and switch on the AC for a few mins. However, I am yet to figure out a way to clean the mist from outside, as the wipers just spread it more rather than cleaning it.

[amtak]

Yes, do as what others have said. It works! I normally use hot air blow to solve this problem.

[CrAzY dRiVeR]

What is this rain setting? I think you mean the windscreen defrost mode.

The layer is formed on the outside of the car. Clearly shows that condensation is occurring on the outside, as you are cooling the windscreen more than it need to be. That means you are using the defrost mode too much, IMO.

As long as you have the a.c on, you should not have any problems with the fogging of the windows. There is no need to switch to defrost mode (rain mode), unless the windows get fogged on the inside. The a.c supplies dehumidified air, and hence won't condense on the inside.

Most owner's manuals also mentions that, once the windscreen becomes clear, the fan should be brought back to normal position with ac on.

[raja748]

Originally Posted by dadu

Try warm air instead of Cold air when using the AC.

The workshop people have asked me not to use heater option when AC is on

[srijit]

What causes fog to form outside the window? Wiper blade problems? How does one solve that, apart from stopping and wiping?

[raja748]

Originally Posted by CrAzY dRiVeR

What is this rain setting? I think you mean the windscreen defrost mode.

The layer is formed on the outside of the car. Clearly shows that condensation is occurring on the outside, as you are cooling the windscreen more than it need to be. That means you are using the defrost mode too much, IMO.

As long as you have the a.c on, you should not have any problems with the fogging of the windows. There is no need to switch to defrost mode (rain mode), unless the windows get fogged on the inside. The a.c supplies dehumidified air, and hence won't condense on the inside.

Most owner's manuals also mentions that, once the windscreen becomes clear, the fan should be brought back to normal position with ac on.

Yes..that is windscreen defrost mode.As soon as rain starts I change AC setting to this mode,with internal air circulation ON.

[raja748]

Originally Posted by nishantgandhi

What do you mean by "changed AC mode to rainy one"?

I faced a similar problem (Getz), but I have seen it with all the other cars as well. There is a foggy layer that keeps getting formed on the windscreen from both inside and outside.

To clean it from inside, I direct the air flow to the windscreen and switch on the AC for a few mins. However, I am yet to figure out a way to clean the mist from outside, as the wipers just spread it more rather than cleaning it.

Hey Nishant,

then how did you tackle this issue of mist from outside?It is really a pain to drive in night when lights of other vehicles fall on your eyes.

[bblost]

Originally Posted by raja748

The workshop people have asked me not to use heater option when AC is on

They are mutually exclusive.
Either you have the heater on or the AC on.
YOu cannot have them both on.

Looks like you need to read the car instruction manual and understand your car better.
I am ony trying to help, please do not misunderstand me.

The dealer/ workshop is trying to give you non-sense answers as they think your knowledge is weak.
A couple of days here and you would be giving them lessons.

But the instruction manual awaits you, first.

[amit_mechengg]

guys its very simple. i face this problem every now and then. just switch your ac to the mode where there is a symbol of blowing the whole air over the windshield. put on the ac and the fan at top speed. if the cabin is warmer than the outside temp then blow cold air on the windscreen. if the cabin is colder than the outside temp just use the heater mode.
the frost vanishes immediately.

[vnabhi]

Hi guys,
I have answers to your questions:-
1. Mist forms on that side of the glass that is hotter. So if it starts raining, it is cold outside, and hot inside the car, leading to mist forming on the inside layer of the windscreen. This can be easily got rid of by switching on the AC in fresh air mode and directing the air towards the windscreen.
2. Mist forms on the outside of the windscreen when it is cooler inside the car. Genrally this happens when the AC cools the interiors to a temperature that is cooler than the outside rain temperature. Most new cars have super efficient ACs that cause this problem. So the solution is to continue using the AC, but also turning on the heater a bit to make the inside temperature more or less equal to the outside. The correct setting comes with trial and error. Once this is achieved, mist on the outside vanishes in no time.
We can draw an analogy to this situation by comparing a bottle of water removed from the fridge--you will notice a layer of mist on the outer surface, as the outside temperature is more than the inside the bottle. So as a general rule, mist forms on the surface that is hotter. So now you know how to counter it. Try it out, guys.

[nishantgandhi]

Originally Posted by raja748

The workshop people have asked me not to use heater option when AC is on

Agreed. even I have been told the same thing by Hyundai.

AC to be used only on Cool mode. On Heater mode, no AC required.

[condor]

Question is why just one side.

@Raja, a few questions for you:
1. Normal way of avoiding fogging of front windshield during rains is to switch on A/c - typically max cooling (to speed up the process) and direct the cooled air towards the windshield only. Fan speed of 1 or 2 would be enough.

Are you doing this much only, or what exactly are you doing ? Pls elaborate.

Suggest you start with the above steps & try changes like faster fan speed. Using warm air is something I am hearing for the first time - but if it works for you also, fine.

2. When this problem has happened, have you stopped the car in a suitable place and checked if there's anything on the windshield outside, where the problem is happening ?

3. Clean the windshield (esp in that area) using a cleaning agent.

4. Sonax has a windshield cleaning agent - a small bottle. Suggest you add this to your windshield spray water reservoir/tank.

5. Try faster wiper speeds initially & things improve, come back to normal speeds (as required).

CrAzY dRiVeR : The layer is formed on the outside of the car. Clearly shows that condensation is occurring on the outside, as you are cooling the windscreen more than it need to be.

Condensation : the act or process of reducing a gas or vapor to a liquid or solid form.

That's one of the meanings, and I think most apt for this situation.

When the car is in rain, there's already water outside. The outside of the glass wouldnt have any further wetting, since it is already wet.