Not able to change airflow, only works on high

I need some help figuring out what is going on. My aircond/heater works temp wise just fine. The airflow speed only works on the highest setting. There is no airflow at any other setting. I was wondering if there was anyway to take care of this on my own. If you have any thoughts, suggestions, or advice I would appreciate your help. Thanks so much.

You probably need to change the fan resistor that is located under the dash. Usually it is located in the area close to the fan motor. You can purchase one of these from a GM Dealer for $30 (only place you can get one) and install it yourself. The resistor isn't hard to change but getting to it can be a problem.