2004 s40 (old version) A/C stops blowing cold air
 

on longer trips in the car (recently, through very hot weather), the a/c will blow cold air fine for a while, then there will be a slight "moldy" smell, then the a/c will cease to blow cold air. the blower still continues to work fine, just no cold air. you can shut the a/c off for a little while, say 10 minutes or so, then it will blow cold again for a little while.

i called volvo and before i could even finish describing the problem they told me it was probably the compressor. other things that other mechanics have suggested:

-a faulty high / low pressure switch
-a faulty sensor (possibly the one that detects the cabin temperature)
-a bad compressor clutch (possibly with a bad connection to the compressor)
-the passenger compartment filter needs to be changed

boy i really hope its just a filter!
hoping you can help! any thoughts?
all the best / peace and joy
volvoDT