Aircon issue - 2008 (late) XTR

[OrangeSpyderMan]

Hi all,

New member here, I have recently acquired a late 2008 XTR (LHD, I'm in France if that matters to the vehicle spec), which I'm happy with except for the aircon...  I initially thought it just needed recharging, which I had done, and it worked for a while, but I now have an issue where it doesn't seem to work for any length of time.

Symptoms :
- AC green light comes on and stays on, even when no cold air is being produced
- Click of the compressor coming on can be heard
- Sometimes it produces cold air briefly ( a few minutes ), other times it either doesn't at all or does so for an imperceptibly short time
- The pipes under the bonnet aren't cold, so this doesn't seem to be an issue with the hot/cold controls on the dash

My understanding is that the compressor wouldn't click on at all if there was a gas pressure issue, but I have to confess I'm at a bit of a loss as to what else I can easily check before biting the bullet and taking it to the dealer.  Is there a clutch on the compressor that could have failed?

Any thoughts?

[Luis Rosa]

Likely you have just enough pressure for the system to start the compressor, but then for some reason gas pressure falls again...not being there enough gas in the circuit for effective cooling...you probably have a big leak in the gas circuit somewhere...Did the workshop where you filled up last time perform a vacuum test to the gas circuits? What was the conclusion?

[OrangeSpyderMan]

Thanks to both. It was vacuum tested with apparently no issues (they are vehicle aircon specialists, and won't recharge without previously testing, and won't recharge at all if there are issues, but of course that doesn't mean there might not still be something awry). It was recharged with a tracer in it so I'll see if I can see something under a UV light.

[Luis Rosa]

In the end you can also have a stuck valve in the gas circuit, that stops the gas from flowing around the circuit and cooling the evaporator. Following the test procedures described in servicebox, this is also described as a potential cause for your symptoms...

[OrangeSpyderMan]

Just to feed back : after a bit of digging, what I can see in Diagbox is "Air conditioning compresor variable capacity valve control fault : short circuit to earth"... I guess that at least gives me a pointer. Guess I'm going to keep digging