Why will my A/C not turn on sometimes? I've noticed this a last couple of days. I'll have it in defrost mode and push the A/C button... the A/C icon will come on on the display but disappear just as fast as it came on.

Then... usually after awhile of driving if I push the A/C button it will come on without any problems. That's usually how it happens however it does happen where it will work when I first turn the car on then not work after driving for a while.

What would be causing this? When it DOES turn on I can hear a "click" sound underneath the left side of the dash by the fuse box. Is that normal?

Any help is greatly appreciated!

Thank You!

 

I have the same problem Does your engine sound whiney at all? Ever since I had this problem after my car was getting fixed the engine has sounded whiney and bad. The shop that had my car said my AC compressor went bad from sitting and that's what the sound's from

 

I've noticed that mine does that when the temperature is below 5C (roughly 41F, the temps that turn on the little snow flake that is an indicator that icy conditions may be present) If that snow flake is present, the a/c won't turn on, above 5C, its no problem. My theory, and any techs can support or correct me if I'm wrong, is that this has to do with the a/c condenser needing to be above a certain temp to function correctly. That or the computer automatically figures that if the ambient temperature is below 5C, no one's going to be wanting a/c on so it doesn't allow it to come on.

 

There is both a low temp cutoff and a low pressure cutoff. If it's too cold or the refrigerant is too low (leak), the A/C compressor will not run as it normally would.

Additionally, the Defogger mode for the HVAC uses the A/C compressor and system to dry out the air it blows on the windshield. The dry air sucks up the moisture on your windshield, thus defogging it. The Defog mode automatically controls the A/C.

I'm not really sure what your conditions are... what is the outside temperature like? Are you using the emergency defog mode or selecting defog and foot vents manually?