The Blower Motor Resistor Pack is defective. Replace it.
I just had that same problem..I took it in to have it fixed and they replaced the blower motor resistor and that seems to have fixed the problem
it needs a blower motor resistor to make the fan settings work.If you replace the Blower MOTOR Resistor it should resolve the problem.
I had this problem with my 2002 Grand Prix where it would only work on high, and even then only worked sometimes. I had to have the whole unit replaced. It was around $400.
If the blower only works on high the blower resistor is most likely the problem and should be replaced. On rare occasions if the car has blown the resistor more than once the blower motor shouuld be replaced.
I had the same problem with the 2003 except the I gradually lost one or two fan settings at a time. There is a resistor unit on the fan itself, behind and below the glove box. It was badly corroded. I replaced the resistor unit and now the fan works on 1 thru 5 settings again.
Defective blower motor resistor pack.
My first guess would be the blower motor speed resister. The second guess would be the switch and/or switch plug. I agree, It's a very common problem, the resistor goes for about $52.00 Can. Carquest has them part # RU44
I had the same problem with the same year car. I've replaced the resistor several times. It works for months & then it stops working again. I think this is the 4th time I replaced the resistor, it is working okay now. I think it is a defect in with this cars fan system. I had a similar problem with my 2001 Sebring Convertible. I had the blower motor replaced, and now the fan works perfectly.
I have a 2001 GTP and just replaced the ignition wiring harness - $129 part from dealership to fix same problem. Now the AC blows on 1-4 + 5 settings. Hope this helps! CIII
The best place I've found to get your brakes replaced is the local muffler man. Any type of smaller garage in your area will be able to take care of your brake problem at a fraction of the cost of taking it to the Pontiac dealership.
Typically a relay or resistor. But could be a blower switch or blower motor problem.