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For 1990-2009 cars only

Auxiliary Blower Motor Malfunction C69

Step

Action

Value

Yes

No

Schematic Reference: HVAC Schematics

Connector End View Reference: HVAC Connector End Views

DEFINITION: The auxiliary 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 auxiliary blower motor switch in each speed position.

Does the auxiliary blower motor operate at the desired speeds?

--

Go to Step 3

Go to Step 4

3

  1. Place the front auxiliary blower motor switch in the rear control position.
  2. Place the rear auxiliary blower motor switch in each speed position.

Does the auxiliary blower motor operate at the desired speeds?

--

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

Go to Step 17

4

  1. Turn OFF the ignition.
  2. Disconnect the auxiliary blower motor.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the auxiliary blower motor speed control circuit of the auxiliary blower motor with a test lamp that is connected to battery positive voltage.
  5. Place the front auxiliary blower motor switch in each speed position.

Does the test lamp illuminate in each speed position?

--

Go to Step 5

Go to Step 6

5

Test the ignition 3 voltage circuit of the auxiliary blower motor for a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 32

Go to Step 25

6

Does the test lamp illuminate in the maximum speed position?

--

Go to Step 11

Go to Step 7

7

Test the ignition 3 voltage circuit of the auxiliary blower motor relay 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 32

Go to Step 8

8

  1. Turn OFF the ignition.
  2. Disconnect the auxiliary blower motor relay.
  3. Turn ON the ignition, with the engine OFF.
  4. Connect a test lamp between the ignition 3 voltage circuit and the high blower motor control circuit of the auxiliary blower motor relay.
  5. Place the front auxiliary blower motor switch in the maximum speed position.

Does the test lamp illuminate?

--

Go to Step 9

Go to Step 10

9

Test the ground circuit of the auxiliary blower motor relay 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 32

Go to Step 22

10

Test the high blower motor control circuit of the auxiliary blower motor relay 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 32

Go to Step 24

11

  1. Turn OFF the ignition.
  2. Disconnect the auxiliary blower motor resistor assembly.
  3. Turn ON the ignition, with the engine OFF.
  4. Measure the resistance between the auxiliary medium 1/2 blower motor control circuit of the auxiliary blower motor resistor assembly and the auxiliary blower motor speed control circuit of the auxiliary blower motor.

Does the resistance measure near the specified value?

0 ohms

Go to Step 13

Go to Step 12

12

Test the auxiliary medium 1/2 blower motor control circuit of the auxiliary blower motor resistor assembly 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 32

Go to Step 22

13

  1. Probe the auxiliary blower motor low speed control circuit with a test lamp that is connected to battery positive.
  2. Place the front auxiliary blower motor switch in the minimum speed position.

Does the test lamp illuminate?

--

Go to Step 14

Go to Step 15

14

  1. Probe the auxiliary blower motor medium speed control circuit with a test lamp that is connected to battery positive.
  2. Place the front auxiliary blower motor switch in the medium speed position.

Does the test lamp illuminate?

--

Go to Step 23

Go to Step 16

15

Test the auxiliary blower motor low speed control circuit of the auxiliary blower motor resistor assembly 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 32

Go to Step 24

16

Test the auxiliary blower motor medium speed control circuit of the auxiliary blower motor resistor assembly 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 32

Go to Step 24

17

Does the auxiliary blower motor operate at all from the rear auxiliary blower motor switch?

--

Go to Step 21

Go to Step 18

18

  1. Turn OFF the ignition.
  2. Disconnect the auxiliary HVAC control module.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the auxiliary blower motor control circuit of the auxiliary HVAC control module with a test lamp that is connected to battery positive voltage.

Does the test lamp illuminate?

--

Go to Step 20

Go to Step 19

19

Test the auxiliary blower motor speed control 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 32

Go to Step 24

20

Test the auxiliary blower motor switch supply voltage 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 32

Go to Step 26

21

Test each auxiliary blower motor speed control 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 32

Go to Step 26

22

Inspect for poor connections at the harness connector of the auxiliary blower motor relay. 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 32

Go to Step 27

23

Inspect for poor connections at the harness connector of the auxiliary 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 32

Go to Step 28

24

Inspect for poor connections at the harness connector of the front auxiliary blower motor switch. 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 32

Go to Step 29

25

Inspect for poor connections at the harness connector of the auxiliary 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 32

Go to Step 30

26

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 32

Go to Step 31

27

Replace the auxiliary blower motor relay.

Did you complete the replacement?

--

Go to Step 32

--

28

Replace the auxiliary blower motor resistor assembly. Refer to Auxiliary Blower Motor Resistor Assembly Replacement .

Did you complete the replacement?

--

Go to Step 32

--

29

Replace the front auxiliary blower motor switch. Refer to Front Auxiliary Blower Motor Switch Replacement .

Did you complete the replacement?

--

Go to Step 32

--

30

Replace the auxiliary blower motor. Refer to Auxiliary Blower Motor Replacement .

Did you complete the replacement?

--

Go to Step 32

--

31

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

Did you complete the replacement?

--

Go to Step 32

--

32

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 3

Auxiliary Blower Motor Malfunction C69 with U32

Step

Action

Value

Yes

No

Schematic Reference: HVAC Schematics

Connector End View Reference: HVAC Connector End Views

DEFINITION: The auxiliary 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 auxiliary blower motor switch in each speed position.

Does the auxiliary blower motor operate at the desired speeds?

--

Go to Step 3

Go to Step 4

3

  1. Place the front auxiliary blower motor switch in the rear control position.
  2. Place the rear auxiliary blower motor switch in each speed position.

Does the auxiliary blower motor operate at the desired speeds?

--

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

Go to Step 17

4

  1. Turn OFF the ignition.
  2. Disconnect the auxiliary blower motor.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the auxiliary blower motor speed control circuit of the auxiliary blower motor with a test lamp that is connected to battery positive voltage.
  5. Place the front auxiliary blower motor switch in each speed position.

Does the test lamp illuminate in each speed position?

--

Go to Step 5

Go to Step 6

5

Test the ignition 3 voltage circuit of the auxiliary blower motor for a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 31

Go to Step 24

6

Does the test lamp illuminate in the maximum speed position?

--

Go to Step 11

Go to Step 7

7

Test the ignition 3 voltage circuit of the auxiliary blower motor relay 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 31

Go to Step 8

8

  1. Turn OFF the ignition.
  2. Disconnect the auxiliary blower motor relay.
  3. Turn ON the ignition, with the engine OFF.
  4. Connect a test lamp between the ignition 3 voltage circuit and the high blower motor control circuit of the auxiliary blower motor relay.
  5. Place the front auxiliary blower motor switch in the maximum speed position.

Does the test lamp illuminate?

--

Go to Step 9

Go to Step 10

9

Test the ground circuit of the auxiliary blower motor relay 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 31

Go to Step 21

10

Test the high blower motor control circuit of the auxiliary blower motor relay 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 31

Go to Step 23

11

  1. Turn OFF the ignition.
  2. Disconnect the auxiliary blower motor resistor assembly.
  3. Turn ON the ignition, with the engine OFF.
  4. Measure the resistance between the auxiliary medium 1/2 blower motor control circuit of the auxiliary blower motor resistor assembly and the auxiliary blower motor speed control circuit of the auxiliary blower motor.

Does the resistance measure near the specified value?

0 ohms

Go to Step 13

Go to Step 12

12

Test the auxiliary medium 1/2 blower motor control circuit of the auxiliary blower motor resistor assembly 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 31

Go to Step 21

13

  1. Probe the auxiliary blower motor low speed control circuit with a test lamp that is connected to battery positive.
  2. Place the front auxiliary blower motor switch in the minimum speed position.

Does the test lamp illuminate?

--

Go to Step 14

Go to Step 15

14

  1. Probe the auxiliary blower motor medium speed control circuit with a test lamp that is connected to battery positive.
  2. Place the front auxiliary blower motor switch in the medium speed position.

Does the test lamp illuminate?

--

Go to Step 22

Go to Step 16

15

Test the auxiliary blower motor low speed control circuit of the auxiliary blower motor resistor assembly 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 31

Go to Step 23

16

Test the auxiliary blower motor medium speed control circuit of the auxiliary blower motor resistor assembly 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 31

Go to Step 23

17

Does the auxiliary blower motor operate at all from the rear auxiliary blower motor switch?

--

Go to Step 20

Go to Step 18

18

  1. Turn OFF the ignition.
  2. Disconnect the auxiliary HVAC control module.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the auxiliary blower motor speed control circuit of the auxiliary HVAC control module with a test lamp that is connected to battery positive voltage.

Does the test lamp illuminate?

--

Go to Step 25

Go to Step 19

19

Test the auxiliary blower motor control 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 31

Go to Step 23

20

Test each auxiliary blower motor speed control 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 31

Go to Step 25

21

Inspect for poor connections at the harness connector of the auxiliary blower motor relay. 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 31

Go to Step 26

22

Inspect for poor connections at the harness connector of the auxiliary 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 31

Go to Step 27

23

Inspect for poor connections at the harness connector of the front auxiliary blower motor switch. 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 31

Go to Step 28

24

Inspect for poor connections at the harness connector of the auxiliary 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 31

Go to Step 29

25

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 31

Go to Step 30

26

Replace the auxiliary blower motor relay.

Did you complete the replacement?

--

Go to Step 31

--

27

Replace the auxiliary blower motor resistor assembly. Refer to Auxiliary Blower Motor Resistor Assembly Replacement .

Did you complete the replacement?

--

Go to Step 31

--

28

Replace the front auxiliary blower motor switch. Refer to Front Auxiliary Blower Motor Switch Replacement .

Did you complete the replacement?

--

Go to Step 31

--

29

Replace the auxiliary blower motor. Refer to Auxiliary Blower Motor Replacement .

Did you complete the replacement?

--

Go to Step 31

--

30

Replace the auxiliary HVAC control module. Refer to Auxiliary Heater and Air Conditioning Control Module Replacement or VES Overhead Console Replacement .

Did you complete the replacement?

--

Go to Step 31

--

31

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 3