93 Cutlass Supreme AC

I have a 1993 Oldsmobile Cutlass Supreme SL... 3.1L V6 and the AC isnt workin, it worked just before winter, and now it doesnt even click on, i dont know if there is some kind of temperature sensore where it has to be hot enough out, and i checked fuses and relays, all seem good, is it possible that my system lost its charge? I dont think it has been retro-fit. any ideas on where to start so i dont have to spend a lot of cash to see whats up.