For 1990-2009 cars

Step | Action | Yes | No
--- | --- | --- | ---
Schematic Reference: HVAC Schematics Connector End View Reference: HVAC 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 the ignition ON, with the engine OFF.
2. Place the blower motor switch in each speed position.

Does the blower motor operate at the desired speeds?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3 |

1. Turn the ignition OFF.
2. Disconnect the blower motor resistor assembly.
3. Turn the ignition ON, with the engine OFF.
4. Probe the LOW, MED 1, MED 2, and HIGH blower motor control circuits at the blower motor resistor assembly, with a test lamp that is connected to battery positive voltage. At the same time, place the blower motor switch in the appropriate speed position for the circuit being tested.

Does the test lamp illuminate on all blower motor control circuits?

Go to Step 5

Go to Step 4

4 | Test the applicable blower motor control circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 10 | Go to Step 7
5 | Test each blower motor control circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 10 | Go to Step 6
6 | Inspect for poor connections at the harness connector of the blower motor resistor assembly. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 10 | Go to Step 8
7 | Inspect for poor connections at the harness connector of 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 10 | Go to Step 9
8 | Replace the blower motor resistor. Refer to Blower Motor Resistor Assembly Replacement . Did you complete the replacement? | Go to Step 10 | --
9 | Replace the HVAC control assembly. Refer to Heater and Air Conditioning Control Replacement . Did you complete the replacement? | Go to Step 10 | --
10 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2