GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2000 🢒 Sunfire 🢒 HVAC 🢒 HVAC Systems - Manual 🢒 Blower Motor Inoperative at Any Speed

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

  1. Replace the fuse and verify proper operation if you are unable to locate the short to ground.

    2.

  2. Replace the fuse and verify proper operation if you are unable to locate the short to ground.

Step

Action

Yes

No

SCHEMATIC REFERENCES: HVAC Blower Control Schematics .

1

Did you perform the HVAC Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - HVAC Systems - Manual

2
  1. Turn ON the ignition, with the engine OFF.
  2. Place the HVAC control in the VENT position.
  3. Place the blower motor switch in each position (1, 2, 3 and 4).

Does the blower motor operate in all speeds?

Go to Symptoms - HVAC Systems - Manual

Go to Step 3

3

Does the blower motor operate in any speed?

Go to Symptoms - HVAC Systems - Manual

Go to Step 4

4

Inspect the HVAC fuse.

Is the HVAC fuse open?

Go to Step 13

Go to Step 5

5

Inspect the BLOWER fuse.

Is the BLOWER fuse open?

Go to Step 14

Go to Step 6

6
  1. Turn OFF the ignition.
  2. Disconnect the blower motor relay.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the positive battery voltage circuit of the blower motor relay with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 7

Go to Step 21

7

Probe the control circuit of the blower motor relay with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 8

Go to Step 12

8

Probe the ground circuit of the blower motor relay with a test lamp that is connected to B+.

Does the test lamp illuminate?

Go to Step 9

Go to Step 24

9

Connect a 30 amp fused jumper wire between the battery positive voltage supply circuit of the blower motor relay and the blower motor supply voltage circuit at the blower motor relay connector.

Does the blower motor operate?

Go to Step 18

Go to Step 10

10
  1. Disconnect the blower motor with the 30 amp fused jumper wire still installed.
  2. Probe the blower motor voltage supply circuit with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 11

Go to Step 22

11

Connect a test lamp between the blower motor voltage supply circuit and the high (position 4) blower motor control circuit.

Does the test lamp illuminate?

Go to Step 20

Go to Step 16

12
  1. Disconnect the HVAC control head.
  2. Probe the HVAC voltage supply circuit with a test lamp connected to a good ground.

Does the test lamp illuminate?

Go to Step 15

Go to Step 23

13

Test the following for a short to ground. Refer to Circuit Testing :

    • HVAC control head voltage supply circuit
    • A/C switch signal circuit
    • Blower motor relay control circuit

Did you find and correct the condition?

Go to Step 29

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

14

Test the following for a short to ground. Refer to Circuit Testing :

    • Blower motor relay voltage supply circuit
    • Blower motor voltage supply circuit
    • Blower motor

Did you find and correct the condition?

Go to Step 29

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

15

Test the blower motor relay control circuit for an open. Refer to Circuit Testing .

Did you find and correct the condition?

Go to Step 29

Go to Step 19

16

Test the high (position 4) blower motor control circuit for an open between the blower motor and the splice. Refer to Circuit Testing .

Did you find and correct the condition?

Go to Step 29

Go to Step 17

17
  1. Disconnect the HVAC control head.
  2. Probe the HVAC control head ground circuit with a test lamp connected to B+.

Does the test lamp illuminate?

Go to Step 19

Go to Step 25

18

Inspect for poor connections at the blower motor relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 29

Go to Step 26

19

Inspect for poor connections at the HVAC control head. 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 29

Go to Step 27

20

Inspect for poor connections at the 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 29

Go to Step 28

21

Repair the open in the blower motor relay voltage supply circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 29

--

22

Repair the open in the blower motor voltage supply circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 29

--

23

Repair the open in the HVAC control head supply voltage circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 29

--

24

Repair the open in the blower motor relay ground circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 29

--

25

Repair the open in the HVAC control head ground circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 29

--

26

Replace the blower motor relay.

Did you complete the replacement?

Go to Step 29

--

27

Replace the HVAC control head. Refer to HVAC Module Assembly Replacement .

Did you complete the replacement?

Go to Step 29

--

28

Replace the blower motor. Refer to Blower Motor and Fan Replacement .

Did you complete the replacement?

Go to Step 29

--

29

Operate the vehicle in order to verify the repair.

Is the repair complete?

System OK

Go to Step 2