GM Service Manual Online
For 1990-2009 cars only

Auxiliary Blower Motor Always On Body Type VIN 3

Step

Action

Yes

No

Schematic Reference: HVAC Schematics

Connector End View Reference: HVAC Connector End Views

DEFINITION: The auxiliary blower motor operates with the auxiliary blower motor switch in the OFF position.

1

Did you perform the HVAC Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - HVAC Systems - Automatic

2

Turn the auxiliary HVAC controls OFF.

Is the auxiliary blower motor OFF?

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

Go to Step 3

3

Disconnect the auxiliary HVAC control module.

Is the auxiliary blower motor OFF?

Go to Step 4

Go to Step 5

4

Inspect for poor connections at the harness connector of the auxiliary HVAC control module. Refer to Wiring Repairs and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 7

Go to Step 6

5

Repair a short to voltage in the appropriate auxiliary blower motor speed control circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 7

--

6

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

Did you complete the replacement?

Go to Step 7

--

7

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3

Auxiliary Blower Motor Always On Body Type VIN 6

Step

Action

Values

Yes

No

Schematic Reference: HVAC Schematics

Connector End View Reference: HVAC Connector End Views

DEFINITION: The auxiliary blower motor operates with the HVAC controls in the OFF position.

1

Did you perform the HVAC Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check - HVAC Systems - Manual

2

  1. Turn the ignition ON, with the engine OFF.
  2. Turn OFF the auxiliary HVAC controls.

Is the auxiliary blower motor OFF?

--

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

Go to Step 3

3

With the scan tool observe the Rear Blower Speed parameter in the REAR HVAC/RSA data list.

Does the scan tool indicate that the Rear Blower Speed parameter is near the specified value?

0%

Go to Step 4

Go to Step 7

4

  1. Turn the ignition OFF.
  2. Disconnect the auxiliary HVAC control module.
  3. Turn ON the ignition, with the engine OFF.

Is the auxiliary blower motor OFF?

--

Go to Step 6

Go to Step 5

5

Test the auxiliary blower motor speed control circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 10

Go to Step 6

6

Inspect for poor connections at the harness connector of the auxiliary blower motor control processor. Refer to Wiring Repairs and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 10

Go to Step 8

7

Inspect for poor connections at the harness connector of the auxiliary HVAC control module. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 10

Go to Step 9

8

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

Did you complete the replacement?

--

Go to Step 10

--

9

Important: Perform the recalibration procedure for the auxiliary HVAC control module.

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

Did you complete the replacement?

--

Go to Step 10

--

10

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 2