Possible air con issue?
 

Only driven the car a couple times over the past week or two, but each time it has taken 15 minutes (at least) to clear the condensation/misting that you get when you first get in. That's 15 mins when the engine is both cold and up to temp. It just about clears to see for driving but is no where near completely gone. Passenger side worse.


In the past once I've pressed DEF all hell breaks loose and within a couple of mins the window is clear - and everyone inside the car is frozen! :icon_wink: Ive got cold air coming out (and it goes hot if I turn the temp up), but it just doesn't clear the misting - like the a/c is not actually working even tho the light is on.


12 months ago I had the a/c completely serviced and its been fine ever since.


How best to go from here folks? All advice greatly appreciated.


Jules

A good place to start would be to confirm the compressor clutch is engaging. If not, check loom and fuses as well as refrigerant level in system.

Thanks


Checked fuses 15 (engine) and 8 (engine bulkhead) and both are fine.


How do I check if the compressor clutch is engaging?

Your post states you have COLD air and HOT air if required. If that is correct then it may not be an AC problem.

AC temperature is controlled by the components boxed in RED; where that air is then directed is controlled by the components boxed in BLUE:

Attachment 207557
(click on the image to enlarge it)

Air distribution is altered by flaps operated by servo motors (circled in RED):

Attachment 207558
(click on the image to enlarge it)

If these motors fail or the flaps stick, airflow cannot be directed to the required outlets.

Can you get hot air at maximum output to the screen vents?

Graham

With the engine running and air conditioning ON, look at the front of the engine on the RH side, when viewed from the front, to see if the compressor clutch is spinning or not. If the clutch is spinning, the compressor is engaged. If it's not spinning, it may be low on refrigerant, or there is an electrical connection fault requiring further diagnosis.

As Graham suggests above, check to see if the air directional flaps are moving as the positions are changed for directing the air to the windscreen.

I'm not sure of the weather in North Devon England, but I wanted to mention/ask: aren't all car A/C units designed not to operate in low, nearly freezing outside temperatures?

John

Thanks. I'm on my holidays from tomorrow so will have a look. Cant believe it would be low on refrigerant though as only refilled 12 months ago.

Thanks too. Haven't driven since, but will take it out for a little run tomorrow and check the hot air to screen situation.

A question on this though. My VW will clear the misting eventually when the AC is not on, but clears it in a couple minutes with it on. Although there is cold air coming out in the Jag, its not very cold and really struggles to clear anything - hence my thought it might be the AC.

Weather here is positively balmy at the moment for this time of year, and has been 8-10'C for the past few days. Down a bit during the night but the issue was tea time and early evening, so no where near freezing.

Jules

Jules,

I was full of sympathy until I read that. :icon_lol:

Graham :icon_cold:

Update...

Clutch is def engaging; still when AC off and spinning like a goodun' when AC on.

After engine fully up to temp, both hot and cold air is hitting the screen dependent on setting used.

Here's the thing. When ive been testing up to now, the air recirculation switch has been off. I decided to try things with it on and there was a definite change in power of the blower (ie more) and I'm convinced the air temp was both colder/hotter when I adjusted up and down.

So my question is, should the air recirculation switch always be ON to ensure maximum benefit when demisting windscreens using AC?

Jules :icon_tree:

It's reasonable to expect the temperature should stabilise to the required AC setting faster with RECIRC than it will on NORMAL where it is constantly drawing in external (ambient) air.

Graham

You can take a 9 volt battery and listen to hear run the servo motors and read the servo position sensors change

Over serviced and the over pressure switch inop ?

See page 110 of linked Doc for DIY self test :

http://www.jagrepair.com/images/Trai...des/703_SG.pdf

Editing



https://cimg8.ibsrv.net/gimg/www.jag...c8eff7ca37.png