GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2006 🢒 SRX 🢒 HVAC 🢒 HVAC Systems - Automatic 🢒 Auxiliary Blower Motor Inoperative

Test Description

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

  1. This step tests to verify that the auxiliary blower motor operates.

    2.

  2. This step determines if the malfunction is on the supply voltage side of the auxiliary blower motor.

    3.

  3. This step determines if the malfunction is the auxiliary blower motor or on the grounding side of the auxiliary blower motor.

Step

Action

Yes

No

Schematic Reference: HVAC Schematics

DEFINITION: The auxiliary blower motor is inoperative in all speed positions.

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

  1. Turn ON the ignition, with the engine OFF.
  2. Turn the auxiliary blower motor switch to high speed

Does the auxiliary blower motor operate?

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 auxiliary blower motor.
  3. Turn ON the ignition, with the engine OFF.
  4. Set the front auxiliary blower motor switch to operate at high speed.
  5. Connect a test lamp between the auxiliary blower motor supply voltage circuit and a good ground.

Does the test lamp illuminate?

Go to Step 4

Go to Step 6

4

Connect a test lamp between the auxiliary blower motor supply voltage circuit and the auxiliary blower motor ground circuit.

Does the test lamp illuminate?

Go to Step 14

Go to Step 5

5

Test the ground circuit of the auxiliary blower motor 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 21

Go to Step 11

6
  1. Turn OFF the ignition.
  2. Disconnect the primary quarter A/C relay.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the ignition 3 voltage circuit of the primary quarter A/C relay with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 7

Go to Step 16

7

Probe the primary quarter A/C relay battery positive voltage circuit with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 8

Go to Step 17

8

Probe the primary quarter A/C relay ground circuit with a test lamp that is connected to battery positive voltage.

Does the test lamp illuminate?

Go to Step 10

Go to Step 9

9

Repair the ground circuit of the primary quarter A/C relay for an open or high resistance. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 21

--

10

Inspect the auxiliary blower motor supply voltage circuit for an open, high resistance or short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 21

Go to Step 13

11
  1. Turn OFF the ignition.
  2. Disconnect the auxiliary blower motor switch.
  3. Probe the auxiliary blower motor ground circuit at the auxiliary blower motor switch with a test lamp that is connected to battery positive voltage.

Does the test lamp illuminate?

Go to Step 15

Go to Step 12

12

Repair the auxiliary blower motor switch ground circuits for an open or high resistance. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 21

--

13

Inspect for poor connections at the harness connector of the primary quarter A/C 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 21

Go to Step 18

14

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 21

Go to Step 20

15

Inspect for poor connections at the harness connector of the 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 21

Go to Step 19

16

Repair the ignition 3 voltage circuit of the primary quarter A/C relay. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 21

--

17

Repair the battery positive voltage circuit of the primary quarter A/C relay. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 21

--

18

Replace the primary quarter A/C relay.

Did you complete the replacement?

Go to Step 21

--

19

Replace front auxiliary blower motor switch. Refer to HVAC Control Module Replacement .

Did you complete the replacement?

Go to Step 21

--

20

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

Did you complete the replacement?

Go to Step 21

--

21

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2