AC Fan problems

My AC fan only blows air when the switch is in the 3rd or 4th position. Does any one know it this is a problem with the switch or fan? Any help would be great.

The problem could be the fan but since it works on positions 3 & 4 it probably is the fan control resistor. This costs about $20 at the GM Dealer, only place you can get one, and should be located under the dash next to the fan motor. Should take about half an hour to an hour to fix. Not hard to do but you may need to remove the fan. If you don't want to do it yourself then take it to the garage as it will take a mechanic about a half an hour to repair.