I'd say ignition switch too.
My sisters 02 GT has this same problem. I swapped blower motors with my car and still did it, I bought a new blower motor resistor and helped but it still will either work on all settings, just on high or it will just stop working altogether. Sometimes it will work on 5 if you turn the car on and it's there but as soon as you go down to 4 is shuts off and if you switch back to 5 it wont work again.
Next set is the ignition swap as that is the whole thing controlling power to it, the part is not to much. Rockauto has a brand new AC DELCO units for 75 bucks I think.
How to remove it and swap new in.
http://www.sparkys-answers.com/2009/...-changing.html
