I had the same problem on a mondeo - dodgy contacts on the switch..hope that helps?
If you are referring to the blower motor speed, and only the highest setting works, then the problem is a bad Blower Motor Resistor Pack.
You need to replace blower motor resistor.
Blower resistor pack broken?
The blower motor speed resistor is probably burned out.
could be the resistor on blower motor is bad
The blower motor resistor pack is defective. Replace it.
Sounds like the blower resistor is burned out.
If you are referring to the blower motor only working on the high speed setting, then the problem is the blower motor Resistor Pack is defective. Replace it. It can be the blower motor speed control switch but not likely.
Defective Blower Motor Resistor Pack.
If you are saying that the blower motor only works on the high speed setting, then the Blower Motor Resistor is defective and needs replacing.
It could be due to a faulty resistor in the blower motor circuit. The resistor regulates the speed of the blower motor, and if it malfunctions, the high speed setting may not work properly. It would be best to have a mechanic inspect and replace the resistor if necessary.
: My 2002 focus blower fan worked at the highest setting only and not 1,2 and 3. I fixed it by replacing the blue resistor pack held down by 1 screw behind the glove box next to the blower motor. : At first I checked the power supply to the blower motor connector. I was getting power only at setting 4 and none at other settings. : Fan blower electrical diagram showed that the only connection to the fan blower is the power supply, resistor pack and front panel switch.