Hi all, having problems with my air con can anyone assist. Air con was working then the car was sat on the drive for a week and now it does not. The air con clutch doesn't engage. I have checked fuse 12 (Climate control) in the passenger compartment and fuse 41 AC clutch in the engine compartment and both were ok. I can manually turn the ac clutch with my fingers. 

I have read that the No gas would stop the ac clutch engaging because the low pressure sensor would obviously sense low pressure and prevent the ac clutch from engaging. Just seems strange that it worked the week before and there are no obvious signs of leakage. I was thinking that maybe it was a sensor fault. I don't have an OBD (One on order) so any clues as to anything else I can do to narrow it down and resolve the problem please.

Thanks in advance.

You are correct that low refrigerant will prevent the compressor clutch from engaging. Most leaks I've seen were on the condenser (looks like the radiator) and it's right behind the front grille in the line of fire of any large stones. Have a good look and make sure there isn't an oily stain anywhere there as the refrigerant gas contains oil. Fingers crossed you don't find anything and it turns out to be something cheaper.

 

Thanks for your reply Matt. I have just looked around and at the condenser but nothing obvious has been leaking. I have ordered a new pollen/cabin filter but when I had the fan on the airflow was good and adjusted in line with the fan speed selection. Just read that an old filter (mine is 4 years old) can cause the flow to reduce sufficiently to trip a different sensor which would also prevent the ac clutch engaging. I am pretty new at car Diy so just trying the easy stuff first as it all worked fine last week. Any other easy checks. Thanks.

I didn't know there was a sensor which monitors the air flow. If you run the cabin fan without the pollen filter fitted then I would assume you'd have the best possible airflow. May be worth a try as a test. Failing that the next step would be to have someone plug in a pressure gauge to check there is still refrigerant in the system.

Thanks again Matt. I will try that then. Might have to wait for the Obd to arrive and see if there are any codes stored. 

No, have the pressures checked. Anything else is guesswork.

Aircon sorted with a refridgerant recharge. There are two types of gas now also. Cars after 2017 have a new eco friendly gas which is twice the cost abd doesn't last as long. Recharge every 3 years or it runs out completely.

Thanks to those who posted advice.

On with the 4 year service which has thrown another snag up. So I have another post now asking for help with the fuel filter.

Not strictly true. My 2017 still blows good and cold. The new gas is very expensive but seems to be no more percolative than R134a, having a similar molecule size.