For 1990-2009 cars

Step | Action | Yes | No
--- | --- | --- | ---
Schematic Reference: HVAC Schematics Connector End View Reference: HVAC Connector End Views DEFINITION: The blower motor is inoperative in all speed positions.
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 | Important: The mode switch must remain in any position except OFF throughout this diagnostic procedure.

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

Does the blower motor operate in any speed position?

Go to Blower Motor Malfunction

Go to Step 3

3 |

1. Turn OFF the ignition.
2. Disconnect the blower motor.
3. Turn ON the ignition, with the engine OFF.
4. Probe the blower motor supply voltage circuit of the blower motor with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 4

Go to Step 7

4 | Connect a test lamp between the blower motor supply voltage circuit and the high blower motor control circuit of the blower motor. Does the test lamp illuminate? | Go to Step 8 | Go to Step 5
5 | Test the high blower motor control circuit for an open, short to voltage or high resistance. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 12 | Go to Step 6
6 | Test the blower motor switch ground circuit of the HVAC control assembly for an open or high resistance. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 12 | Go to Step 9
7 | Repair the blower motor supply voltage circuit . Refer to Circuit Testing and Wiring Repairs . Did you complete the repair? | Go to Step 12 | --
8 | Inspect for poor connections at the blower motor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 12 | Go to Step 10
9 | Inspect for poor connections at the HVAC control assembly. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 12 | Go to Step 11
10 | Replace the blower motor. Refer to Blower Motor Replacement . Did you complete the replacement? | Go to Step 12 | --
11 | Replace the HVAC control assembly. Refer to Heater and Air Conditioning Control Replacement . Did you complete the replacement? | Go to Step 12 | --
12 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2