Flowchart No 1: Blower Motor Inop at Any Switch Position

System Operation
Blower motor speed is controlled by the fan switch and a resistor in the blower unit. When the fan switch is at OFF, the motor ground circuit is open and the blower motor does not operate. When the switch is in the first position, current flow from the blower motor is restricted by the resistor, and the blower motor turns at low speed.

Changing the fan switch to the second, third, or fourth positions causes the circuit resistance to decrease and the blower motor speed to increase.

Step 1
1. Check the following fuses.







2. If the fuses are OK, go to Step 2.
3. If a fuse is burnt, check for a short-circuit in the harness before replacing the fuse.

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







3. Measure the voltage at the terminal wires of the blower relay connector.


Step 3
1. Verify that the ignition switch is at ON and that the fan switch is in the fourth position.







2. Measure the voltage at the terminal wires of the blower motor connector.


Step 4
1. Verify that the ignition switch is at ON.
2. Turn the fan switch off.







3. Measure the voltage at the (L/W) terminal wire of the fan switch.


Step 5
1. Disconnect the fan switch connector.







2. Check for continuity between the (B) terminal wire of the fan switch connector and ground.