Problems with my Aircon on my Mazda 6 2005

[tony tbg]

Hi, I recently bought a Mazda 6 ts2 2005, I'm having issues with my air con. I've had the car for about a week and the aircon after about 30 minutes the air would eventually turn cold but not as cold as it should be, so today i got it recharged thinking that would rectify the probelm.However it hasen't the aircon isn't turning cold at all now. A few days ago when the engine was idleing when you press the aircon button you can hear the engine ref's die, however today at kwik fit they said you couldn't here the motor kick in? Can anyone please give advice

[Dr Doofenshmirtz]

Well, it's not a motor, it's a compressor...but I wouldn't expect the braindead mouth-breathers at Kwik Fit to know that or be ale to properly diagnose the issue...useless idiots.

Anyway -
There is an over and under pressure sensor. My guess, assuming the system is properly pressurised is that one of those sensors had failed?
The first thing you need to do is pressure test the system. Kwik Fit really should have done this? The low side valve should be at around 45psi, and drop a little when running.

[tony tbg]

Hi, thanks for your reply. i agree with what you said about Kwik Fit, however one thing they did do for me is totally empty then pressurised the tank then refilled the aircon tank, so to that end I now know the tank is full and the system is pressurised. Today i have been looking into the problem i have, With the engine idling when i pressed the aircon button the they was definitely a drop in engine rev's, telling me the compressor was engaging. So i think these sensor you where talking about could be the problem. If i replace them will that cause the tank to depressurise? by any chance do you know what they look like and where they would be locatated?

Thanks again for your help.