On my audi I first (2002a4,1.I first started to hear a whirring when compressor came on had the used Carlton mechanic check it out . First replaced the serpentine belt ...that did not help so when the comp kicked on thier seem to be more whurring noises and the a.c. was full and cool but that whurring would pop on and I would shut the comp off with the econo by pass button. Next repair was the high speed fan ...after the mechanics replaced that the econo switch will not shut off ..any suggestions for next move im thinking it could be compressor and or econo not h9ked right any suggestions

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