Hi all
could you please tell me how do i know if the air con is working and if its working properly on mk4 mondeo diesel
thanks
steve...................

 

ideally this should be checked my an expect but there are things u can try yourself.firstly is the compressor going round when ac is switched on,it will be a click when u switch it on from engine bay when running and normally located on the bottom of the engine.secondly youd want a thermometer in the air vents and switch ac on its coldest setting and see how low the temp drops.
thats just a couple of things im sure others will come up with some other ideas

 

Someone's gotta say it... Does it get cold in your car when it's turned on, lol. If it does, it's working

But in all seriousness, B19 JUB is spot on!

 

as above really if the compressor doesnt audibly click on then its not working, at idle when switching on the revs will drop ever so slightly for half a second or so

 

Coldest setting, full recirc, lift the revs slightly, should get cold, ensure compressor belt ain't snapped, condenser pipes should get warmer one side than the other

 

Check to see if the air con pump is working.When you turn the air con on the pump should click as the clutch in the pulley engages and starts to work.If it doesnt the air con gas might be low.

 

not all compressors have a clutch these days, some are permanently on and change their displacement according to load.

to properly test it you need to load it hard, i.e. have a hot (> 40deg.C day with full sunlight) environment, and measure the subcool out of the condenser and the superheat out of the evaporator as well as vent temperatures. obviously that is beyond the average DIYer and garage, so realistically it does just mean checking operation (vent temperature and demisting), but again in cold weather like this it is very easy to achieve low vent temperatures with a low refrigerant charge but it would struggle when it warms up.

why do you suspect it's not, or are you looking for advice when viewing to buy?

 

I have purchasede the car but i want to see if its working ok before warrenty runs out