Chevrolet Repair: a/c not working, c button, clutch

Question
2001 suburban K1500 5.3 65000 mi
Air was working fine end of last season, but clutch does not engage.  checked fuses, belt, all ok.  clutch face spins freely, just will not engage when a\c button is pressed.  is there anything else i can check before taking to dealer?  is there some other (safety) reason clutch will not engage (i.e. - low refrigerant)?

thanks
steve  

Answer
are you talking about the ac?/ and tha ac has a clutch?? hmmm new one on me. im not much for ac but i will try to help. i see ya did the checking already, so what to do next. hmm take it to the shop and telll me all about it so i can help others.. sorry i could be of more help.