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Makes 🢒 Buick 🢒 2001 🢒 Regal (China) 🢒 HVAC 🢒 HVAC Systems - Manual 🢒 Blower Motor Malfunction

Blower Motor Malfunction CJ3

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This step tests the output of the blower motor switch in each speed position and through each blower motor control circuit.

  2. Test the circuit that did not illuminate the test lamp in Step 5.

Step

Action

Yes

No

Schematic Reference: HVAC Schematics

DEFINITION: The blower motor operates in at least one, but not 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
  1. Turn ON the ignition, with the engine OFF.
  2. Place the blower motor switch in each speed position.

Does the blower motor operate at the desired speed in each speed positions?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

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. Connect a test lamp between the blower motor supply voltage circuit and a good ground.
  5. Place the blower motor switch in each speed position.

Does the test lamp illuminate in each speed position?

Go to Step 7

Go to Step 4

4
  1. Turn OFF the ignition.
  2. Disconnect the blower motor resistor assembly connector.
  3. Turn ON the ignition, with the engine OFF.
  4. 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 12

5

Important: The blower motor switch must be in the correct speed position for the blower motor control circuit being tested.

  1. Probe each blower motor control circuit with a test lamp that is connected to a good ground.
  2. Place the blower motor switch in the appropriate speed position for the blower motor control circuit being tested.

Does the test lamp illuminate in each speed position?

Go to Step 10

Go to Step 6

6

Test the appropriate blower motor control circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 16

Go to Step 11

7
  1. Connect a test lamp between the blower motor supply voltage circuit and the blower motor ground circuit.
  2. Place the blower motor switch in each speed position.

Does the test lamp illuminate in each speed position?

Go to Step 9

Go to Step 8

8

Test the ground circuit of the blower motor resistor assembly for a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 16

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 16

Go to Step 13

10

Inspect for poor connections at the harness connectors of the blower motor resistor assembly. 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

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 16

Go to Step 15

12

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 16

--

13

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

Did you complete the replacement?

Go to Step 16

--

14

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

Did you complete the replacement?

Go to Step 16

--

15

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

Did you complete the replacement?

Go to Step 16

--

16

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3

Blower Motor Malfunction CJ4

Step

Action

Yes

No

Schematic Reference: HVAC Schematics

DEFINITION: The blower motor operates in at least one, but not 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
  1. Turn ON the ignition, with the engine OFF.
  2. Place the front blower motor switch in each speed position.

Does the blower motor operate in each speed position?

Go to Step 3

Go to Step 4

3

Place the auxiliary blower motor switch in each speed position.

Does the auxiliary blower motor operate in each speed position?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 10

4
  1. Measure the voltage from the auxiliary blower motor speed control circuit of the auxiliary HVAC control module to a good ground.
  2. Place the blower motor switch from the minimum speed position to the maximum speed position.

Does the measured voltage change?

Go to Step 6

Go to Step 5

5

Test the auxiliary blower motor speed control circuit of the auxiliary HVAC control module for an open, high resistance, 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 22

Go to Step 16

6
  1. Install a scan tool.
  2. With a scan tool, observe the Fan Up Button parameter in the Heating and Air Conditioning data list.
  3. Activate the fan up switch.
  4. Observe the Fan Down Button parameter in the Heating and Air Conditioning data list.
  5. Activate the fan down switch.

Does the scan tool indicate that Fan Up Button and Fan Down Button parameters change state?

Go to Step 7

Go to Step 17

7
  1. Turn OFF the ignition.
  2. Disconnect the blower motor.
  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 control circuit of the blower motor.
  5. 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 15

Go to Step 8

8

Test the battery positive voltage circuit of the blower motor control processor for a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 22

Go to Step 9

9

Test the ground circuit of the blower motor control processor for an high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 22

Go to Step 14

10

Test the ignition-3 voltage circuit of the auxiliary HVAC control module for an open, high resistance or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 22

Go to Step 11

11

Test the ground circuit of the auxiliary HVAC control module for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 22

Go to Step 12

12
  1. Measure the voltage from the auxiliary blower motor speed control circuit of the auxiliary HVAC control module to a good ground.
  2. Activate the blower motor switch in each direction.

Does the measured voltage change?

Go to Step 17

Go to Step 13

13

Test the auxiliary blower motor speed control circuit of the auxiliary HVAC control module for an open, high resistance, 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 22

Go to Step 16

14

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 22

Go to Step 18

15

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 22

Go to Step 19

16

Inspect for poor connections at the harness connector of the auxiliary 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 22

Go to Step 20

17

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 22

Go to Step 21

18

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

Did you complete the replacement?

Go to Step 22

--

19

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

Did you complete the replacement?

Go to Step 22

--

20

Replace the auxiliary HVAC control module. Refer to Auxiliary Heater and Air Conditioning Control Replacement .

Did you complete the replacement?

Go to Step 22

--

21

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

Did you complete the replacement?

Go to Step 22

--

22

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3