* No heat or air coming from the vents, even though the fan is running
* The fan only works on one speed
* The fan is noisy or makes a grinding sound
* The blower motor resistor may be bad.
To check the blower motor resistor, you will need a multimeter.
1. Turn off the ignition and disconnect the battery.
2. Locate the blower motor resistor. It is usually located near the blower motor, behind the glove box or under the passenger footwell.
3. Disconnect the electrical connector from the blower motor resistor.
4. Set the multimeter to the ohms setting.
5. Touch one probe of the multimeter to each terminal on the blower motor resistor.
6. The resistance should be between 0.1 ohms and 10 ohms.
7. If the resistance is infinite (OL), the blower motor resistor is bad and will need to be replaced.
Replacing the Blower Motor Resistor
1. Disconnect the battery.
2. Locate the blower motor resistor.
3. Disconnect the electrical connector from the blower motor resistor.
4. Remove the mounting screws that hold the blower motor resistor in place.
5. Pull the blower motor resistor out of the housing.
6. Transfer the mounting screws from the old resistor to the new one.
7. Insert the new resistor into the housing.
8. Tighten the mounting screws.
9. Connect the electrical connector to the new resistor.
10. Connect the battery.
