I've been having trouble with the a/c on my 2004, 2.3. When I start up the a/c and I have the windows down you can hear, what can be described as a 'scratching' noise, throughout operation of the a/c but it disappears when I turn the a/c off. Also, my a/c doesn't seem to blow out any cold air. Could this just be that I'm out of a/c fluid or is it something worse...

 

Almost sounds like the clutch on the AC compressor is gone