For 1990-2009 cars

Step | Action | Yes | No
--- | --- | --- | ---
Schematic Reference: HVAC Schematics . Connector End View Reference: Component Connector End Views . DEFINITION: The blower motor operates in at least one, but not all, speed positions.
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle .
2 |

1. Turn ON the ignition, with the engine OFF.
2. Place the blower motor switch in each speed position.

Are any blower speeds available?

Go to Step 4

Go to Step 3

3 | Check for blown blower motor fuse 9 Was the fuse blown? | Replace the fuse with the correct amperage fuse. | Go to Step 4
4 | Check for power at the blower motor. Circuit Testing and Wiring Repairs . Is voltage available, but the blower motor will not operate? | Replace the blower motor. Refer to Blower Motor Replacement . | Go to Step 5
5 |

1. Operate all the blower speeds, one at a time at the IRC blower control.
2. There should be 20 blower speeds available.

Are all blower speeds available?

Go to Step 9

Go to Step 6

6 |

1. Back probe the 2 pin connector at the blower motor.
2. Activate the 20 blower fan speeds one at a time starting from the lowest, using the IRC blower control.
3. Compare the voltages to the graph. Refer to Sensor Resistance Table .

Were the voltages approximate to the graph?

Go to Step 9

Go to Step 7

7 | Connect scan tool. Go to miscellaneous test, switch data. Select all 20 blower fan speeds using the scan tool increase / decrease soft keys Were all speeds available? | Carry out IRC test for blower switch function. | Go to Step 8
8 | Replace the HVAC control module. Refer to HVAC Control Module Replacement . Did you find and correct the condition? | Go to Step 9 | --
9 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2