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Makes 🢒 GMC_Truck 🢒 2000 🢒 Savana 🢒 HVAC 🢒 HVAC Systems - Manual 🢒 Blower Motor Always On - Auxiliary Air Conditioning (A/C)

Blower Motor Always On - Auxiliary Air Conditioning (A/C) Cargo Van

Step

Action

Value(s)

Yes

No

DEFINITION:

    • The rear auxiliary blower motor operates at all times.
    • Vehicle is a cargo van equipped with rear A/C (C69).

1

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

--

Go to Step 2

Go to Symptoms

2
  1. Place the ignition switch in the RUN position.
  2. Place the front HVAC control module in the OFF position.

Does the blower motor operate?

--

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

Go to Step 3

3
  1. Disconnect the following components:
    2. • The auxiliary blower motor.
    • The auxiliary blower motor resistor.
    • The auxiliary blower motor high speed relay.
    • The auxiliary blower motor medium speed relay.
    • The auxiliary blower motor low speed relay.
  2. Connect a J 35616-200 unpowered test lamp between auxiliary blower motor connector cavity B for CKT 1172 (YEL) and ground. Refer to Circuit Testing in Wiring Systems.

Does the test lamp illuminate?

--

Go to Step 14

Go to Step 4

4

Connect a J 35616-200 unpowered test lamp between auxiliary blower motor resistor cavity A for CKT 1176 (YEL) and ground. Refer to Circuit Testing in Wiring Systems.

Does the test lamp illuminate?

--

Go to Step 15

Go to Step 5

5

Connect a J 35616-200 unpowered test lamp between auxiliary blower motor resistor connector cavity C for CKT 1072 (LT BLU) and ground. Refer to Circuit Testing in Wiring Systems.

Does the test lamp illuminate?

--

Go to Step 16

Go to Step 6

6
  1. Connect the auxiliary blower motor resistor.
  2. Connect the auxiliary blower motor.
  3. Connect the auxiliary blower motor low speed relay.

Does the auxiliary blower motor operate?

--

Go to Step 7

Go to Step 9

7

Disconnect the front auxiliary HVAC control module.

Does the auxiliary blower motor cease operating?

--

Go to Step 20

Go to Step 8

8
  1. Disconnect the auxiliary blower motor relay.
  2. Connect a J 39200 DMM between auxiliary blower motor low speed relay connector cavity A1 for CKT 1926 (DK BLU) and ground. Refer to Circuit Testing in Wiring Systems.

Is continuity present?

--

Go to Step 17

Go to Step 21

9

Connect the auxiliary blower motor medium speed relay.

Does the auxiliary blower motor operate?

--

Go to Step 10

Go to Step 12

10

Disconnect the front auxiliary HVAC control module.

Does the auxiliary blower motor cease operating?

--

Go to Step 20

Go to Step 11

11
  1. Disconnect the auxiliary blower motor medium speed relay.
  2. Connect a J 39200 DMM between auxiliary blower motor medium speed relay connector cavity A1 for CKT 1925 (RED) and ground. Refer to Circuit Testing in Wiring Systems.

Is continuity present?

--

Go to Step 18

Go to Step 22

12
  1. Disconnect the front auxiliary HVAC control module.
  2. Connect a J 39200 DMM between front auxiliary HVAC module connector cavity D and cavity F. Refer to Circuit Testing in Wiring Systems.

Is continuity present?

--

Go to Step 19

Go to Step 13

13

Connect a J 39200 DMM between front auxiliary HVAC control module pin D and pin F. Refer to Circuit Testing in Wiring Systems.

Is continuity present?

--

Go to Step 20

Go to Step 23

14

Repair the short to voltage in CKT 1172 (YEL) between the auxiliary blower motor connector, auxiliary blower motor resistor connector, and the auxiliary blower motor high speed relay connector.

Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 24

--

15

Repair the short to voltage in CKT 1176 (YEL) between the auxiliary blower motor resistor connector and the auxiliary blower motor low speed relay connector.

Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 24

--

16

Repair the short to voltage in CKT 1072 (LT BLU) between the auxiliary blower motor resistor connector and the auxiliary blower motor medium speed relay connector.

Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 24

--

17

Repair the short to ground in CKT 1926 (DK BLU)/CKT 60 (YEL) between the front auxiliary HVAC control module connector and the auxiliary blower motor low speed relay connector.

Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair ?

--

Go to Step 24

--

18

Repair the short to ground in CKT 1925 (RED)/63 (TAN) between the front auxiliary HVAC control module connector and the auxiliary blower motor medium speed relay connector.

Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 24

--

19

Repair the short to ground in CKT 1924 (WHT)/CKT 52 (ORN) between the front auxiliary HVAC control module connector and the auxiliary blower motor high speed relay connector.

Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 24

--

20

Replace the front auxiliary HVAC control module.

Refer to Auxiliary Air Conditioning (A/C) Control Assembly Replacement - Front .

Did you complete the repair?

--

Go to Step 24

--

21

Replace the auxiliary blower motor low speed relay.

Did you complete the repair?

--

Go to Step 24

--

22

Replace the auxiliary blower motor medium speed relay.

Did you complete the repair?

--

Go to Step 24

--

23

Replace the auxiliary blower motor high speed relay.

Did you complete the repair?

--

Go to Step 24

--

24

Operate the auxiliary blower motor in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 3

Blower Motor Always On - Auxiliary Air Conditioning (A/C) Passenger Van

Step

Action

Value(s)

Yes

No

DEFINITION:

    • The rear auxiliary blower motor operates at all times.
    • Vehicle is a passenger van equipped with rear A/C (C69).

1

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

--

Go to Step 2

Go to Symptoms

2
  1. Place the ignition switch in the RUN position.
  2. Place the front auxiliary HVAC control module in the OFF position.
  3. Place the rear auxiliary HVAC control module in the OFF position.

Does the blower motor operate?

--

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

Go to Step 3

3
  1. Disconnect the following components:
    2. • The auxiliary blower motor.
    • The auxiliary blower motor resistor.
    • The auxiliary blower motor high speed relay.
    • The auxiliary blower motor medium speed relay.
    • The auxiliary blower motor low speed relay.
  2. Place the ignition switch in the RUN position.
  3. Connect a J 35616-200 unpowered test lamp between auxiliary blower motor connector cavity B for CKT 1172 (YEL) and ground.

Does the test lamp light?

--

Go to Step 16

Go to Step 4

4

Connect a J 35616-200 unpowered test lamp between auxiliary blower motor resistor cavity A for CKT 1176 (YEL) and ground.

Does the test lamp light?

--

Go to Step 17

Go to Step 5

5

Connect a J 35616-200 unpowered test lamp between auxiliary blower motor resistor connector cavity C for CKT 1072 (LT BLU) and ground.

Does the test lamp light?

--

Go to Step 18

Go to Step 6

6
  1. Connect the auxiliary blower motor resistor.
  2. Connect the auxiliary blower motor.
  3. Connect the auxiliary blower motor low speed relay.

Does the auxiliary blower motor operate?

--

Go to Step 7

Go to Step 10

7

Disconnect the front auxiliary HVAC control module.

Does the auxiliary blower motor cease operating?

--

Go to Step 19

Go to Step 8

8

Disconnect the rear auxiliary HVAC control module.

Does the auxiliary blower motor cease operating?

--

Go to Step 20

Go to Step 9

9
  1. Disconnect the auxiliary blower motor low speed relay.
  2. Connect a J 39200 digital multimeter (DMM) between auxiliary blower motor low speed relay connector cavity A1 for CKT 1926 (DK BLU) and ground.

Is continuity present?

--

Go to Step 21

Go to Step 22

10

Connect the auxiliary blower motor medium speed relay.

Does the auxiliary blower motor operate?

--

Go to Step 11

Go to Step 14

11

Disconnect the front auxiliary HVAC control module.

Does the auxiliary blower motor cease operating?

--

Go to Step 19

Go to Step 12

12

Disconnect the rear auxiliary HVAC control module.

Does the auxiliary blower motor cease operating?

--

Go to Step 20

Go to Step 13

13
  1. Disconnect the auxiliary blower motor medium speed relay.
  2. Connect a J 39200 DMM between auxiliary blower motor medium speed relay connector cavity A1 for CKT 1925 (RED) and ground.

Is continuity present?

--

Go to Step 23

Go to Step 24

14
  1. Disconnect the front auxiliary HVAC control module.
  2. Connect a J 39200 DMM between front HVAC control module connector cavity D and cavity B.

Is continuity present?

--

Go to Step 15

Go to Step 19

15
  1. Disconnect the rear auxiliary HVAC control module.
  2. Connect a J 39200 DMM between rear HVAC control module connector cavity D and cavity B.

Is continuity present?

--

Go to Step 25

Go to Step 26

16

Repair the short to voltage in CKT 1172 (YEL) between the auxiliary blower motor connector, auxiliary blower motor resistor connector, and the auxiliary blower motor high speed relay connector.

Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 27

--

17

Repair the short to voltage in CKT 1176 (YEL) between the auxiliary blower motor resistor connector and the auxiliary blower motor low speed relay connector.

Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 27

--

18

Repair the short to voltage in CKT 1072 (LT BLU) between the auxiliary blower motor resistor connector and the auxiliary blower motor medium speed relay connector.

Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 27

--

19

Replace the front auxiliary HVAC control module.

Refer to Auxiliary Air Conditioning (A/C) Control Assembly Replacement - Front .

Is the repair complete?

--

Go to Step 27

--

20

Replace the rear auxiliary HVAC control module.

Refer to Control Assembly Replacement - Auxiliary in Overhead Console .

Is the repair complete?

--

Go to Step 27

--

21

Repair the short to ground in CKT 1926 (DK BLU)/60 (YEL) between the following components:

    • The front auxiliary HVAC control module connector.
    • The rear auxiliary HVAC control module connector.
    • The auxiliary blower motor low speed relay connector.

Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 27

--

22

Replace the auxiliary blower motor low speed relay.

Is the repair complete?

--

Go to Step 27

--

23

Repair the short to ground in CKT 1925 (RED)/63 (TAN) between the following components:

    • The front auxiliary HVAC control module connector.
    • The rear auxiliary HVAC control module connector.
    • The auxiliary blower motor medium speed relay connector.

Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 27

--

24

Replace the auxiliary blower motor medium speed relay.

Is the repair complete?

--

Go to Step 27

--

25

Repair the short to ground in CKT 1924 (WHT)/52 (ORN) between the following components:

    • The rear auxiliary HVAC control module connector.
    • The front auxiliary HVAC control module connector.
    • The auxiliary blower motor high speed relay connector.

Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 27

--

26

Replace the auxiliary blower motor high speed relay.

Is the repair complete?

--

Go to Step 27

--

27

Operate the auxiliary blower motor in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 3