Blower Motor Does Not Operate

Normal Operation Of Blower Motor
Blower motor speed is controlled by the fan switch and a resistor in the blower unit. When the fan switch is in the OFF position, the motor ground circuit is open and the blower motor does not operate. When the switch is in the first (Low) position, current flow from the blower motor is restricted by the three resistors in the resistor, and the blower motor turns at low speed.

Changing the fan switch to the second (Mid), third (High), or fourth (Super-high) position causes the circuit resistance to decrease, and the blower motor speed becomes correspondingly faster.

Step 1







1. Check the circuit breaker.
2. If the reset button is not out, go to Step 2.
3. If the reset button is out, check for a short circuit in the harness.
Repair as necessary; then depress the reset button to reset the circuit breaker.


Step 2
1. Turn the ignition switch to ON.
2. Turn the fan switch to the fourth position.








3. Measure the voltage at the A terminal wire of the blower motor connector.


Step 3
1. Verify that the ignition switch is at ON.
2. Turn the fan switch off and verify that the A/C switch is off.








3. Measure the voltage at the terminal wires of the resistor.


Step 4
1. Turn the ignition switch to ON.
2. Turn the fan switch to the fourth position.








3. Measure the voltage at the G terminal wire of the fan switch connector.


Step 5
1. Verify that the ignition switch is at ON.
2. Turn the fan switch off and verify that the A/C switch is off.








3. Measure the voltage at the terminal wires of the fan switch connector.