GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2000 🢒 Blazer - 4WD - RHD 🢒 HVAC 🢒 HVAC Systems - Automatic 🢒 Blower Motor Inoperative at Any Speed

Step

Action

Value(s)

Yes

No

1

Was the Diagnostic System Check performed?

--

Go to Step 2

Go to Diagnostic System Check

2

Verify that the blower motor is inoperative at any speed.

Does the blower motor operate normally?

--

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

Go to Step 3

3

Inspect the HVAC fuse located in the underhood fuse block.

Is the HVAC fuse open?

--

Go to Step 4

Go to Step 7

4
  1. Disconnect the PWM power module connector at the blower motor.
  2. Connect a J 39200 .
  3. Measure the resistance of the load site of the HVAC fuse, terminal B to the battery ground.
  4. Leave the meter connected until the test is complete or until you are told to remove it. The load side of the fuse is the terminal without battery voltage and the ignition switch in RUN.

Is the reading less than the specified value?

0.5 ohms

Go to Step 5

Go to Step 6

5

Repair the short to ground in CKT 540 (ORN).

Is the repair complete?

--

Go to Step 22

--

6
  1. Replace the HVAC fuse.
  2. Operate the blower motor.

Does the motor operate correctly?

--

Go to Step 22

Go to Step 12

7
  1. Disconnect the PWM power module connector.
  2. Connect a test lamp between the blower motor drive module connector terminals A and B.

Does the test lamp light?

--

Go to Step 8

Go to Step 9

8
  1. Connect the blower motor drive module.
  2. Turn the ignition switch to the ON position.
  3. Set the electronic climate control module to a midrange position.
  4. Connect a J 39200 .
  5. Backprobe the electronic climate control module connector C16 to ground.

Is the reading within the specified range?

2-4 V

Go to Step 12

Go to Step 15

9

Connect a test lamp between the blower motor connector terminal B and the battery ground.

Does the test lamp light?

--

Go to Step 11

Go to Step 10

10

Repair an open in CKT 540 (ORN).

Is the repair complete?

--

Go to Step 22

--

11

Repair an open in CKT 850 (BLK).

Is the repair complete?

--

Go to Step 22

--

12
  1. Disconnect the blower motor connector and PWM power module.
  2. Connect a jumper wire from the PWM power module terminal B to the blower motor RED terminal.

    3. Caution: The jumpers must be of adequate gauge in order to handle the blower motor current.

  3. Connect a jumper wire from the PWM power module A to the blower motor BLK terminal.

Does the blower motor operate at maximum speed?

--

Go to Step 14

Go to Step 13

13

Replace the blower motor.

Is the repair complete?

--

Go to Step 22

--

14

Replace the PWM power module.

Is the repair complete?

--

Go to Step 22

--

15

Note the readings from the scan tool.

Is the reading equivalent to the specified value?

0 V

Go to Step 16

Go to Step 22

16
  1. Turn the ignition switch to the OFF position.
  2. Disconnect the electronic climate control module electrical connector.
  3. Disconnect the PWM power module electrical connector.
  4. Connect a test lamp between the PWM power module connector terminals B and C.

Does the test lamp light?

--

Go to Step 17

Go to Blower Has High Speed Only

17

Repair a short to ground in CKT 760 (PPL/WHT).

Is the repair complete?

--

Go to Step 22

--

18

Connect a test lamp between the PWM power module harness terminals A and C.

Does the test lamp light?

--

Go to Step 19

Go to Step 20

19

Repair a short to battery in CKT 760 (PPL/WHT).

Is the repair complete?

--

Go to Step 22

--

20

Replace the PWM power module.

Does the blower motor operate correctly?

--

Go to Step 22

Go to Step 21

21

Replace the electronic climate control module.

Is the repair complete?

--

Go to Step 22

--

22

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 3