GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Was the heater-A/C control Diagnostic System Check performed?

--

Go to Step 2

Go to Diagnostic System Check

2

Inspect the HVAC fuse in the fuse block.

Is the HVAC fuse open?

--

Go to Step 3

Go to Step 4

3

Locate and repair a short to ground in circuit 41 (BRN). Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 13

--

4

  1. Turn the ignition switch off.
  2. Disconnect the right temperature control actuator motor electrical connector.
  3. Turn the ignition switch on.
  4. Use a digital multimeter (DMM) in order to measure the voltage between the right electric actuator harness connector terminal 5 and ground.

Is the measured voltage within the specified range?

9-14V

Go to Step 6

Go to Step 5

5

Locate and repair a poor connection or an open in circuit 41 (BRN). Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 13

--

6

  1. Use a DMM in order to measure the voltage between the right electric actuator harness connector terminal 6 and ground.
  2. Vary the passenger temperature knob from full cold to full hot.

Does the voltage vary within the specified range?

0.5- 4.5V

Go to Step 7

Go to Step 8

7

Replace the right electric actuator. Refer to Temperature Actuator Replacement (RH) .

Is the repair complete?

--

Go to Step 13

--

8

Inspect for short to ground or short to B+ in circuit 1236 (WHT/BLK). Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Is there a short to ground or short to B+ in circuit 1236 (WHT/BLK)?

--

Go to Step 9

Go to Step 10

9

Repair the short to ground or short to B+ in circuit 1236 (WHT/BLK). Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 13

--

10

Inspect for a poor connection or open in circuit 1236 (WHT/BLK) between the heater-A/C control harness connector terminal C6 and the right electric actuator harness connector terminal 6. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Is there continuity in circuit 1236 (WHT/BLK)?

--

Go to Step 11

Go to Step 12

11

Repair the poor connection or open in circuit 1236 (WHT/BLK) between the heater-A/C control harness connector terminal C6 and the right electric actuator harness connector terminal 6.

Is the repair complete?

--

Go to Step 13

--

12

Replace the heater-A/C control. Refer to Control Assembly Replacement .

Is the repair complete?

--

Go to Step 13

--

13

Verify that the system operates properly.

Does the system operate properly?

--

System OK

Go to Diagnostic System Check