GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2008 🢒 Optra 🢒 HVAC 🢒 HVAC - Manual 🢒 Blower Motor Malfunction

Step

Action

Values

Yes

No

Schematic Reference: HVAC Schematics

Connector End View Reference: Component Connector End Views

1

Verify the customer's complaint.

Are the customer's concerns verified?

--

Go to Step 2

System OK

2

Turn the blower ON.

Does the blower run at any speed?

--

Go to Step 14

Go to Step 3

3
  1. Disconnect the power connector from the blower motor under the dashboard on the passenger side of the vehicle.
  2. Turn the ignition ON.
  3. Turn the blower ON.
  4. Test for voltage on the connector. The terminal connected to the violet wire is positive and the terminal connected to the black wire is negative.

Does the voltage measure within the specified range?

11-14 V

Go to Step  4

Go to Step 5

4

Replace the blower motor.

Did you complete the replacement?

--

System OK

--

5

Inspect fuse F7 in the I/P fuse block in the engine fuse block.

Is the fuse open?

--

Go to Step  6

Go to Step 7

6
  1. Turn the ignition ON.
  2. Use a short detector to locate a possible short in the following locations:
    3. • Fuse panel-to-blower speed switch
    • Blower speed switch-to-heater resistor block
    • Heater resistor block-to-blower motor
    • Blower speed switch-to-blower HI relay
  3. Repair any short.
  4. Replace any blown fuse.

Did you find and correct the condition?

--

System OK

--

7
  1. Turn the ignition ON.
  2. Set the blower switch on 4.
  3. Inspect the blower motor ground.

Is the ground OK?

--

Go to Step  9

Go to Step  8

8

Repair the blower motor ground.

Did you complete the repair?

--

System OK

--

9

Inspect the motor connector with a 12-volt test light.

Does the test light come on?

--

Go to Step 10

Go to Step 11

10

Repair the open in the feed wire from the resistor block to the blower motor.

Did you complete the repair?

--

System OK

--

11

Use the 12-volt test light to Inspect the power feed terminal on the blower speed switch.

Does the light come on?

--

Go to Step 12

Go to Step 13

12

Replace the blower speed switch.

Did you complete the replacement?

--

System OK

--

13

Repair the open in the power wire from the blower speed switch to the fuse panel.

Did you complete the repair?

--

System OK

--

14

Turn the blower on speed 4.

Does the blower fail to operate at speed 4?

--

Go to Step 15

Go to Step 21

15

Inspect fuse EF3 in the engine fuse block.

Is the fuse open?

--

Go to Step 16

Go to Step 17

16
  1. Turn the ignition ON.
  2. Turn the blower motor switch to 4.
  3. Use a short detector to locate a possible short in the following locations:
    4. • Engine fuse panel-to-blower HI relay.
    • Blower HI relay-to-blower motor.
  4. Repair any short.
  5. Replace the EF3 fuse.

Did you find and correct the condition?

--

System OK

--

17
  1. Turn the ignition switch ON.
  2. Set the blower switch to 4.
  3. Inspect for 12 volts on the blower HI relay coil terminal from the blower speed switch terminal A7.

Is this voltage present?

--

Go to Step 18

Go to Step 19

18

Replace the blower speed switch.

Did you complete the replacement?

--

System OK

--

19
  1. Turn the ignition OFF.
  2. Inspect for opens in the following locations:
    3. • EF3 fuse-to-blower HI relay
    • Blower speed switch-to-blower HI relay
    • Blower HI relay-to-ground
    • Blower HI relay-to-blower motor
  3. Repair any opens.

Did you find and correct the condition?

--

System OK

Go to Step 20

20

Replace the blower HI relay.

Did you complete the replacement?

--

System OK

--

21
  1. Disconnect the resistor block connector.
  2. Connect one lead of a self-powered test light to any single lead on the resistor block. Use the other lead to probe each of the other 2 terminals.

Does the test light illuminate on all terminals?

--

Go to Step 23

Go to Step 22

22

Replace the resistor block.

Did you complete the replacement?

--

System OK

--

23
  1. Turn the ignition to LOCK.
  2. Disconnect the connector from the resistor block.
  3. Connect a jumper lead from the positive terminal on the battery to any wire terminal in the connector.
  4. Use a 12-volt test light to check for voltage from the corresponding wire on the blower speed switch.
  5. Repeat the same test on the other wires.

Does the lamp light on all 3 wires?

--

Go to Step 25

Go to Step 24

24

Replace the blower speed switch.

Did you complete the replacement?

--

System OK

--

25

Repair the open in the affected wire.

Did you complete the repair?

--

System OK

--