Blower Motor Inoperative

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

Step	Action	Value(s)	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 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 blower switch in each speed position. Does the blower motor operate in any of the speed positions?	-	Go to Blower Motor Malfunction	Go to Step 3
3	Turn OFF the ignition. Disconnect the blower motor connector. Turn ON the ignition, with the engine OFF. Connect a test lamp between the blower motor supply voltage circuit and the blower motor control circuit. Place the blower motor switch in the minimum speed position. Does the test lamp illuminate?	-	Go to Step 9	Go to Step 4
4	Test the battery positive voltage circuit of the blower motor control processor for an open, a high resistance or a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	-	Go to Step 15	Go to Step 5
5	Test the ground circuit of the blower motor control processor for an open or a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	-	Go to Step 15	Go to Step 6
6	IMPORTANT: Ensure that the blower motor control processor connector and the HVAC control module connectors are connected during this step in order to avoid misdiagnosis. Measure the voltage from the blower motor speed control circuit at the HVAC control module to a good ground. Place the blower motor switch from the OFF position to the maximum speed position. Does the voltage measure near the specified values for each state?	5.0 V OFF 1.0 V Max.	Go to Step 10	Go to Step 7
7	Turn OFF the ignition. Disconnect the HVAC control module. Turn ON the ignition, with the engine OFF. Measure the voltage from the blower motor speed control circuit of the HVAC control module to a good ground. Does the voltage measure near the specified value?	5.0 V	Go to Step 11	Go to Step 8
8	Test the blower motor speed control circuit of the HVAC control module for an open, short to ground or short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	or	Go to Step 15	Go to Step 10
9	Inspect for poor connections at the harness connector of the blower motor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?	-	Go to Step 15	Go to Step 12
10	Inspect for poor connections at the harness connector of the blower motor control processor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?	-	Go to Step 15	Go to Step 13
11	Inspect for poor connections at the harness connector of the HVAC control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?	-	Go to Step 15	Go to Step 14
12	Replace the blower motor. Refer to Blower Motor Replacement in Heating, Ventilation and Air Conditioning. Did you complete the replacement?	-	Go to Step 15	-
13	Replace the blower motor control processor. Refer to Blower Motor Replacement . Did you complete the replacement?	-	Go to Step 15	-
14	Replace the HVAC control module. Refer to HVAC Control Assembly Replacement . Did you complete the replacement?	-	Go to Step 15	-
15	Operate the system in order to verify the repair. Did you correct the condition?	-	System OK	Go to Step 2