Hi there.Last time i had a/c on suddenly started a "wooing" noise and after some minutes stopped to blow cold air.So i switched it off and stopped on a highway autogrill for a cigarette and refreshments as temp was close to 40d and driving without ac was not possible even with open windows.When i restarted the trip the a/c normally worked but only for abt 30min and noise started again.I started to press various buttons and when i pressed "program" noise stopped but also cold air.I switched off "program" and a/c back to normal again?????
Can such a noise be because of not enough freon in system or sounds like a pump problem?

Mine started making a whining noise when it was low a while back, had it regassed and now the noise is gone

The 'Prog' button will stop the AC and put the car into 'Defrost Program'

Many people say that if you have cold air you dont need a regass - I can catagorically state that is wrong, low gas will cause strange symptoms like cold air on left hot air on right, take it from me I've experienced it.

Many thanks for your reply and definetely first step will be to refill gas and let's hope problem will be solved.