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Makes 🢒 Chevrolet 🢒 2001 🢒 Express 🢒 HVAC 🢒 HVAC Systems - Manual 🢒 Air Delivery Improper - Auxiliary

Air Delivery Improper - Auxiliary Passenger Van With Auxiliary A/C

Step

Action

Value(s)

Yes

No

Schematic Reference: HVAC Schematics

DEFINITION: Air does not flow correctly from the auxiliary air distribution outlets.

1

Did you review the HVAC operation and perform the necessary inspections?

--

Go to Step 2

Go to Symptoms - HVAC Systems - Manual

2
  1. Turn ON the ignition, with the engine OFF.
  2. Place the rear auxiliary blower motor switch in the maximum speed position.
  3. Place the front auxiliary blower motor switch in the OFF position.

Is the auxiliary blower motor OFF?

--

Go to Step 3

Go to Auxiliary Blower Motor Always On

3
  1. Place the front auxiliary blower motor switch in the rear control position.
  2. Place the rear auxiliary blower motor switch in the OFF position.

Is the auxiliary blower motor OFF?

--

Go to Step 4

Go to Auxiliary Blower Motor Always On

4
  1. Turn ON the park lamps.
  2. Place the instrument panel dimmer switch in the brightest position.
  3. Place the front auxiliary blower motor switch in each speed position

Does the auxiliary blower motor operate in any speed position?

--

Go to Step 5

Go to Auxiliary Blower Motor Inoperative

5

Does the auxiliary blower motor operate in each speed position?

--

Go to Step 6

Go to Auxiliary Blower Motor Malfunction

6
  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 properly in each speed position?

--

Go to Step 7

Go to Auxiliary Blower Motor Malfunction

7
  1. Place the front auxiliary blower motor switch in the maximum speed position.
  2. Gradually change the front auxiliary mode switch from the vent position to the floor position.

Does the air flow from the proper air distribution outlets?

--

Go to Step 8

Go to Step 9

8

Important: The park lamps must remain ON, with the instrument panel dimmer switch in the brightest position during this step.

  1. Place the front auxiliary blower motor switch in the rear control position.
  2. Place the rear auxiliary blower motor switch in the maximum speed position.
  3. Gradually change the rear auxiliary mode switch from the vent position to the floor position.

Does the air flow from the proper air distribution outlets?

--

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

Go to Step 19

9
  1. Place the front auxiliary blower motor switch in the rear control position.
  2. Place the rear auxiliary blower motor switch in the maximum speed position.
  3. Gradually change the rear auxiliary mode switch from the vent position to the floor position.

Does the air flow from the proper air distribution outlets?

--

Go to Step 16

Go to Step 10

10
  1. Turn OFF the ignition.
  2. Disconnect the auxiliary mode actuator.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the ignition 3 voltage circuit of the auxiliary mode actuator with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

--

Go to Step 11

Go to Step 28

11

Test the ground circuit of the auxiliary mode actuator 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 33

Go to Step 12

12
  1. Measure the voltage from the auxiliary mode door control circuit of the auxiliary mode actuator and ground.
  2. Gradually change the rear auxiliary mode switch from the vent position to the floor position.

Does the measured voltage continuously increase between the minimum specified value (vent position) and the maximum specified value (floor position)?

0 V (VENT)

B+ (FLOOR)

Go to Step 23

Go to Step 13

13

Test the auxiliary mode door control circuit between the auxiliary mode actuator and the auxiliary HVAC control processor 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 33

Go to Step 14

14

Test the ignition 3 voltage circuit of the auxiliary HVAC control processor 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 33

Go to Step 15

15

Test the ground circuit of the auxiliary HVAC control processor 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 33

Go to Step 27

16
  1. Turn OFF the ignition.
  2. Disconnect the auxiliary HVAC control processor.
  3. Turn ON the ignition, with the engine OFF.
  4. Place the front auxiliary blower motor switch in the minimum speed position.
  5. At the auxiliary HVAC control processor connector, measure the voltage from the auxiliary mode door control circuit of the front auxiliary HVAC control assembly to ground.
  6. Gradually change the front auxiliary mode switch from the vent position to the floor position.

Does the measured voltage continuously increase between the minimum specified value (vent position) and the maximum specified value (floor position)?

0 V (VENT)

B+ (FLOOR)

Go to Step 27

Go to Step 17

17

Test the auxiliary mode door control circuit between the front auxiliary HVAC control assembly and the auxiliary HVAC control processor 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 33

Go to Step 18

18

Test the ignition 3 voltage circuit of the front auxiliary HVAC control 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 33

Go to Step 25

19

Important: The park lamps must remain ON, with the instrument panel dimmer switch in the brightest position during this step.

  1. Turn OFF the ignition.
  2. Disconnect the auxiliary HVAC control processor.
  3. Turn ON the ignition, with the engine OFF.
  4. At the auxiliary HVAC control processor connector, measure the voltage from the auxiliary mode door control circuit of the rear auxiliary HVAC control assembly to ground.
  5. Gradually change the rear auxiliary mode switch from the vent position to the floor position.

Does the measured voltage continuously increase between the minimum specified value (vent position) and the maximum specified value (floor position)?

0 V (VENT)

B+ (FLOOR)

Go to Step 27

Go to Step 20

20

Test the auxiliary mode door control circuit between the rear auxiliary HVAC control assembly and the auxiliary HVAC control processor 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 33

Go to Step 21

21

Test the ignition 3 voltage circuit of the rear auxiliary HVAC control 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 33

Go to Step 22

22

Test the ground circuit of the rear auxiliary HVAC control 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 33

Go to Step 26

23

Inspect the auxiliary mode door and auxiliary mode actuator for the following:

  1. An incorrectly installed actuator
  2. Broken or binding linkages
  3. Obstruction that prevents the auxiliary mode door from operating within it's full range of motion

Did you find and correct the condition?

--

Go to Step 33

Go to Step 24

24

Inspect for poor connections at the harness connector of the auxiliary mode actuator. 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 33

Go to Step 29

25

Inspect for poor connections at the harness connector of the front auxiliary HVAC control 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 33

Go to Step 30

26

Inspect for poor connections at the harness connector of the rear auxiliary HVAC control 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 33

Go to Step 31

27

Inspect for poor connections at the harness connector of the auxiliary HVAC 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 33

Go to Step 32

28

Repair the ignition 3 voltage circuit of the auxiliary mode actuator. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 33

--

29

Replace the auxiliary mode actuator. Refer to Auxiliary Mode Valve Actuator Replacement .

Did you complete the repair?

--

Go to Step 33

--

30

Replace the front auxiliary HVAC control assembly. Refer to Auxiliary Heater and Air Conditioning Control Replacement - Front .

Did you complete the repair?

--

Go to Step 33

--

31

Replace the rear auxiliary HVAC control assembly. Refer to Auxiliary Heater and Air Conditioning Control Replacement - Rear .

Did you complete the repair?

--

Go to Step 33

--

32

Replace the auxiliary HVAC control processor. Refer to Auxiliary HVAC Control Processor Replacement .

Did you complete the repair?

--

Go to Step 33

--

33

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 3

Air Delivery Improper - Auxiliary Cargo Van With Auxiliary A/C

Step

Action

Value(s)

Yes

No

Schematic Reference: HVAC Schematics

DEFINITION: Air does not flow correctly from the auxiliary air distribution outlets.

1

Did you review the HVAC operation and perform the necessary inspections?

--

Go to Step 2

Go to Symptoms - HVAC Systems - Manual

2
  1. Turn ON the ignition, with the engine OFF.
  2. Place the auxiliary blower motor switch in the OFF position.

Is the auxiliary blower motor OFF?

--

Go to Step 3

Go to Auxiliary Blower Motor Always On

3
  1. Turn ON the park lamps.
  2. Place the instrument panel dimmer switch in the brightest position.
  3. Place the auxiliary blower motor switch in each speed position.

Does the auxiliary blower motor operate in any speed position?

--

Go to Step 4

Go to Auxiliary Blower Motor Inoperative

4

Does the auxiliary blower motor operate in each speed position?

--

Go to Step 5

Go to Auxiliary Blower Motor Malfunction

5
  1. Place the auxiliary blower motor switch in the maximum speed position.
  2. Gradually change the auxiliary mode switch from the vent position to the floor position.

Does the air flow from the proper air distribution outlets?

--

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

Go to Step 6

6
  1. Turn OFF the ignition.
  2. Disconnect the auxiliary mode actuator.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the ignition 3 voltage circuit of the auxiliary mode actuator with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

--

Go to Step 7

Go to Step 15

7

Test the ground circuit of the auxiliary mode actuator 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 18

Go to Step 8

8
  1. Measure the voltage from the auxiliary mode door control circuit of the auxiliary mode actuator and ground.
  2. Gradually change the auxiliary mode switch from the vent position to the floor position.

Does the measured voltage continuously increase between the minimum specified value (vent position) and the maximum specified value (floor position)?

0 V (VENT)

B+ (FLOOR)

Go to Step 12

Go to Step 9

9

Test the auxiliary mode door control circuit of the auxiliary mode actuator 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 18

Go to Step 10

10

Test the ignition 3 voltage circuit of the front auxiliary HVAC control 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 18

Go to Step 11

11

Test the ground circuit of the front auxiliary HVAC control 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 18

Go to Step 14

12

Inspect the auxiliary mode door and auxiliary mode actuator for the following:

  1. An incorrectly installed actuator
  2. Broken or binding linkages
  3. Obstruction that prevents the auxiliary mode door from operating within it's full range of motion

Did you find and correct the condition?

--

Go to Step 18

Go to Step 13

13

Inspect for poor connections at the harness connector of the auxiliary mode actuator. 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 18

Go to Step 16

14

Inspect for poor connections at the harness connector of the front auxiliary HVAC control 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 18

Go to Step 17

15

Repair the ignition 3 voltage circuit of the auxiliary mode actuator. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 18

--

16

Replace the auxiliary mode actuator. Refer to Auxiliary Mode Valve Actuator Replacement .

Did you complete the repair?

--

Go to Step 18

--

17

Replace the front auxiliary HVAC control assembly. Refer to Auxiliary Heater and Air Conditioning Control Replacement - Front .

Did you complete the repair?

--

Go to Step 18

--

18

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 3