91 pontiac 6000 ~ AC/Heater Blower fan problems

Hi, im new to this whole... forum thingy... and ive desperately been trying to find answers to my problem. I own a 91 pontiac 6000. Its been operating pretty well so far... till now. My problem is that my heater and ac van blower stopped working. When i want to heat up the cabin (the place i sit in and others) it wont blow air period. I can hear the ducts changing over from vent to floor when i move the slider on the controller... but no air comes through any vents or do i hear the moter for the fan going. I also tried moving the speed thingy up or down and it doesnt change the fact that there is no air comming through anything. Ive checked the fuses inside the glove box and the 25 volt fuse for the ac/heater is fine... any thing else i may concider doing? im really in need of assistance.... when the winter hits.... heating is needed indeed. as for the heat in the summer... i just roll a window down. but i'd really like to have this problem sorted out asap. SOOO PLEASE HELP ME!!! please.