Blower Motor Malfunction

WARNING: This page is about a different car, the 2004 Pontiac Aztek and 2004 Buick Rendezvous. However, it is still accessible from the selected car via links, so may be relevant.

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 in every speed position.
1	Did you perform the HVAC Diagnostic System Check?	Go to Step 2	Go to Diagnostic System Check - HVAC Systems - Manual
2	Turn ON the ignition, with the engine OFF. Place the mode switch in the vent position. Place the blower motor switch in each speed position. Does the blower motor operate in each speed position?	Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems	Go to Step 3
3	Turn OFF the ignition. Disconnect the blower motor. Turn ON the ignition, with the engine OFF. Connect a test lamp between the supply voltage circuit of the blower motor and a good ground. Place the blower motor switch in each speed position. Does the test lamp illuminate when the blower motor switch is in each speed position?	Go to Step 7	Go to Step 4
4	Turn OFF the ignition. Disconnect the blower motor resistor assembly connector. Turn ON the ignition, with the engine OFF. Connect a test lamp between the battery positive voltage circuit of the blower motor resistor assembly and a good ground. Does the test lamp illuminate?	Go to Step 5	Go to Step 10
5	IMPORTANT: The blower motor switch must be in the correct speed position for the blower motor control circuit being tested. Probe each blower motor control circuit with a test lamp that connects to a good ground. Place the blower motor switch in the appropriate speed position for the control circuit being tested. Does the test lamp illuminate when the blower motor switch is in each speed position?	Go to Step 8	Go to Step 6
6	Test the suspected control circuit for an open. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 14	Go to Step 9
7	Inspect for bad connections at the harness connector of the blower motor assembly. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 14	Go to Step 11
8	Inspect for bad connections at the harness connectors of the blower motor resistor assembly. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 14	Go to Step 12
9	Inspect for bad connections at the harness connector of the HVAC control module. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 14	Go to Step 13
10	Repair the battery positive voltage circuit of the blower motor resistor assembly. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?	Go to Step 14	-
11	Replace the blower motor. Refer to Blower Motor Replacement in Heating, Ventilation and Air Conditioning. Did you complete the replacement?	Go to Step 14	-
12	Replace the blower motor resistor assembly. Refer to Blower Motor Resistor Assembly Replacement in Heating, Ventilation and Air Conditioning. Did you complete the replacement?	Go to Step 14	-
13	Replace the HVAC control module. Refer to HVAC Control Module Replacement (Buick) or HVAC Control Module Replacement (Pontiac) . Did you complete the replacement?	Go to Step 14	-
14	Operate the system in order to verify the repair. Did you correct the condition?	System OK	Go to Step 3