On my 2 year old fiesta when I switch the heater to the window direction (on heat setting) it automatically switches on the air con. Can any one tell me is this cooling the air (and working against the heat setting) or simply taking moisture out of the heated air? appreciate your advice.

This is normal. It climatises the car in such a way as to clear the windscreen as quick as possible which as you say is by taking the moisture out of the air and heating it

+1

It clears much faster with the aircon switch on.

hey,

to stop it coming on i just leave it on the last dot before the W/S clear bit and it doesnt turn on but still blows out air to the W/S - do you have heated W/S? as i use this most of the time and clears it really quick

Luke

It takes the moisture out of the air when set on hot or cold

It takes the moisture out of the air when set on hot or cold

Yep.

thanks for the feedback, I have been avoiding using the air con to demist the windscreen but now i know it removes moisture I will leave it on.

i am still not sure if i have the a/c light on but the heat control turned up as well there is a conflict between heating and cooling or if the a/c works in a mode to dehumidify without cooling which would be ideal to demist ( ie heat with dehumidify). the manual says the air con doesn't come on below 4 degrees i have a manual control for the air con not automatic. any comments please?

Make sure to use your air con at least once a fortnight - otherwise the seals will dry out, the gas will leak out and it won't work full stop.

Air con works both hot and cold, it just depends on the temperature setting you have it on. It'll work just like your regular blower but dehumidifies as well.

you bring a good point with putting air con on regularly as i havent put it on in a while and when i do it does tick every 30-40 seconds, and i dont want it drinkning my pertol hehe. but i shall put it on on the way home from work (10 miles at 70MPH) and ill do it again on the weekend - i forget that i have to put it on regularly!!

i may need the air con gas or what ever it is looked at on my next serive at ford. they charge like 60 i think for it but i dont want it breaking as knowing my luck the sun will come out including a heat wave (unpredictable british weather) and then be boiling in the car lol

On my 2 year old fiesta when I switch the heater to the window direction (on heat setting) it automatically switches on the air con. Can any one tell me is this cooling the air (and working against the heat setting) or simply taking moisture out of the heated air? appreciate your advice.

thanks good infomation supplied. i will certainly be using air con /demisting function effectively from now on.