Demister Problem.

[boardy]

Model. S type 2.7 Diesel reg.2005.
I have always had the aircon on summer & winter.During this winter the demister has stopped working, there is no air at all coming from the windscreen vents even when the defrost button is used. I have had a reply from David Marks who suggested I get the car diagnosed to try and get some idea of the fault.Has anyone had a similar problem, or any idea's would be gratefully recieved before I go to the expense of taking it the Jaguar dealer.

[J44EAG]

Take a look on the Electrical section of this BB and go to S-type electrical guide.

Try these links also.

http://api.viglink.com/api/click?format ... 0213399733

http://www.google.co.uk/url?sa=t&rct=j& ... sQ&cad=rja

Mike

[boardy]

Thanks Mike will have a look.

[humbrol]

Hi everyone. Been a long time since I have had time to get on the forum so just catching up. Misting is a problem that I am experiencing but not I believe because of any failing of the system. As many will now I work nights and drive all accross the midlands for work. Now that the cold, damp, foggy weather is here I am starting to struggle.

Without warning my screen will suddenly mist over and it happens almost instantly. On a recent drive to Buxton on the worst bit of the A6 between Blackwell and Buxton The bit with all the curves in it) it happened. The top right side of the screen started to fog over and within seconds the whole screen was opaque. I switched on every combination that I could think ofto try to get it to clear whilst at the same time trying to drive through a 3 inch high section clear sectionat the bottom center of the screen trying to stay on the road not hit a wall and trying ti find somewhere to pull up. Finnally came to a stop and it took a full 5 minutes to clear the screen.

This has happened on the motorway at 70+ miles an hour in towns at 30 all sorts. The rear screen is perminantely fogged and I have to keep switching the heated screen on. The side windows, well, there is anothe story. They remind me of the days driving my 1960s' Mini when evrything was perminantely misted up. A bit embarrassing when you pull up at lights in your so called prestige car and have to wind the window down to see if the traffic lights have changed only to find a 20 year old Fiesta next to you that has all its windows crystal clear.

Has anyone come accross this? Am I using the wrong air con settings or does anyone have any idea how I can stop this potentially dangerous thing happening.

All contributions greatfully received

Iain

[J44EAG]

Time to see an aircon man, Iain.

Hot/cold conditions ie dew point and high ambient humidity at a particular time will cause fogging. A similar situation will occur almost instantly if you get into the car with wet clothing under the right conditions.

That is the best I can offer. The aircon perhaps needs some attention.

Mike

[christopherspeed59]

When the temparature drops below about 3c, the air con compressor will not operate, and so your air con will just work as a heater with no moisture removed from the air. This is to protect the compressor for some reason, but thats as much as i know. Perhaps your pollen filter has moisture in it otherwise even a normal heater should keep the screen clear. I had an astra years ago, and the filter in that would get wet when washing the car and cause no end of problems with misting.

[stuarthardy]

Sounds like a problem I had in my Audi when the heater matrix sprung a leak. The only answer there was to turn the heater off such that the valve closed off the coolant flow. Obviously had to replace the heater matrix too.

I also find that cars fitted with air con (as opposed to climate control) will not demist unless the air con is on. If your air con doesn't work below 3C then I can see it being a problem.

Pollen filter is another good call, make sure it isn't clogged. Check that you are getting hot and cold air delivered to the vents as per the owners handbook.

Oh yes, make sure you are not re-circulating the cabin air as that can give the same effect.