Could be the fan switch but also could be the blower resistor located behind the glove box in the heater case The heater speeds are normally achieved by placing resisters in line with the 12V power supplied to the blower. When some speeds work and others don't it is often because the resister for that speed has failed. The switch is probably OK. The resisters are normally mounted on the blower motor. I don't know the details of the Saturn but the resistor bank is normally serviced without the need to replace the whole blower motor assembly. If you have a meter and can measure resistance, you will probably find the largest resistor has failed. You may be able to replace it with one from Radio Shack. Good Luck
Get a new switch.
Your heater switch may not need to be replaced. The heater high position is controlled by a fuse under the hood. Until you find the fuse and replace it, your new switch will not work. JRR.
Not knowing what year, make and model you have, I would suspect the heater fan switch and or electrical plug to the switch is at fault.
replace the blower fan resistor located under the dash behind the glove box
2001 dodge ram 1500 ac and heater flow regulator switch does not work. works only on defrost. How to fix?
if the blower motor works most likely heater core is bad. need more info
If a 2000 Grand Am sometimes has the heater blower working and sometimes it won't, the problem could be with the heater relay switch. The heater relay switch lets the heater blower know when to come on and when to go off. In most vehicles this switch is behind the glove compartment. This part sometimes gets corroded from condensation in this area.
If the heater still works the bulb is just burn out. I doubt you can change the light you will have to replace the switch.
when the relay is working, it's energizing the blower... jump power to the motor, (be the relay!) to see if the blower works... also, listen to see if the relay is clicking "on" when you turn the switch on the dash(could be a switch) good luck d
Replace the blower motor resistor.
it is usally a dry connection on the fan speed switch
On most makes of cars this problem is fixed by replacing a blower motor resister and not the switch.