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 - Automatic

1. Turn ON the ignition, with the engine OFF.
2. Place the blower motor 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

1. Turn OFF the ignition.
2. Disconnect the blower motor connector.
3. Turn ON the ignition, with the engine OFF.
4. Connect a test lamp between the blower motor supply voltage circuit and the blower motor ground circuit.
5. Place the blower motor switch in the maximum speed position.
6. Place the air temperature switch to the warmest position.

Does the test lamp illuminate?

Go to Step 10

Go to Step 4

1. Disconnect the blower motor control processor.
2. Connect a test lamp between the battery positive voltage circuit and the ground circuit of the blower motor control processor.

Does the test lamp illuminate?

Go to Step 8

Go to Step 5

Connect a test lamp between the battery positive voltage circuit of the blower motor control processor and a good ground.

Does the test lamp illuminate?

Go to Step 7

Go to Step 6

Repair the battery positive voltage circuit of the blower motor control processor. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 16

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Repair the ground circuit of the blower motor control processor. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 16

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1. Connect a volt meter between the blower motor speed control circuit and the battery positive voltage circuit of the blower motor control processor.
2. Observe the volt meter.
3. Place the blower motor switch from the minimum speed position to the maximum speed position.

Does the voltage increase when the blower speed is increased?

Go to Step 11

Go to Step 9

Test the blower motor speed control circuit of the blower motor control processor 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?

Go to Step 16

Go to Step 12

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 16

Go to Step 13

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 16

Go to Step 14

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 16

Go to Step 15

Replace the blower motor. Refer to Blower Motor Replacement in Heating, Ventilation and Air Conditioning.

Did you complete the replacement?

Go to Step 16

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Replace the blower motor control processor. Refer to Blower Motor Control Processor Replacement .

Did you complete the replacement?

Go to Step 16

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Important: Perform the recalibration procedure for the HVAC control module.

Replace the HVAC control module. Refer to HVAC Control Module Replacement .

Did you complete the replacement?

Go to Step 16

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Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2