GM Service Manual Online
For 1990-2009 cars only

Step

Action

Values

Yes

No

Schematic Reference: HVAC Schematics

1

Measure the voltage between terminal 4 and terminal 5 of the mode motor.

Is the voltage measured within the specified range?

11-14 V

Go to Step 3

Go to Step 2

2

  1. Inspect fuse F7.
  2. Inspect the connector and circuit (Brown and Black) for any wiring or terminal problems.
  3. Repair any problems found.

Did you find and correct the condition?

--

System OK

Go to Step 3

3

  1. Using the Motor Control Table, measure the voltages at the specified terminals of the specified motor connectors. Refer to Motor Control Table .
  2. Change the mode settings and observe the voltage changes.

Are the voltages measured as specified in the Motor Control Table?

--

Go to Step 4

Go to Step 5

4

Replace the motor that does not operate properly.

Did you complete the replacement?

--

System OK

--

5

  1. Using the Motor Control Table, measure the voltages at the specified terminals of the specified controller connectors. Refer to Motor Control Table .
  2. Change the mode settings and observe the voltage changes.

Are the voltages measured as specified in the Motor Control Table?

--

Go to Step 6

Go to Step 7

6

  1. Inspect the wiring harness and connectors between the controller and the motor that is not performing properly.
  2. Repair or replace the wiring harness or the defective terminal.

Did you find and correct the condition?

--

System OK

--

7

Inspect the connector at the controller.

Is there a defective terminal?

--

Go to Step 8

Go to Step 9

8

Repair or replace the terminal.

Did you find and correct the condition?

--

System OK

--

9

Replace the controller.

Did you complete the replacement?

--

System OK

--