Was the Diagnostic System Check performed?

--

Go to Step 2

Go to Diagnostic System Check

Inspect the HVAC fuse in the underhood bussed electrical center (UBEC).

Is the HVAC fuse open?

--

Go to Step 3

Go to Step 6

1. Disconnect the blower motor control module connector.
2. Connect a J 39200 .

Important: The load side of the fuse is the terminal without battery voltage and the ignition switch in RUN.

3. Measure the resistance of the load side of the HVAC fuse to the battery ground.
4. Leave the meter connected until the test is complete or until you are told to remove it.

Is the reading less than the specified value?

0.5ohms

Go to Step 4

Go to Step 5

Repair the short to ground in CKT 540.

Is the repair complete?

--

Go to Diagnostic System Check

--

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

Does the motor operate correctly?

--

Go to Diagnostic System Check

Go to Step 11

1. Disconnect the blower motor control 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 7

Go to Step 8

1. Connect the blower motor control module.
2. Turn the ignition switch to the ON position.
3. Set the heater and A/C control module to a midrange position.
4. Connect a J 39200 .
5. Backprobe the heater and A/C control module connector C16 to ground.

Is the reading within the specified range?

2-4V

Go to Step 11

Go to Step 14

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

Does the test lamp light?

--

Go to Step 10

Go to Step 9

Repair an open in CKT 540.

Is the repair complete?

--

Go to Diagnostic System Check

--

Repair an open in CKT 850.

Is the repair complete?

--

Go to Diagnostic System Check

--

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

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

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

Does the blower motor operate at maximum speed?

--

Go to Step 13

Go to Step 12

Replace the blower motor.

Is the repair complete?

--

Go to Diagnostic System Check

--

Replace the blower motor control module.

Is the repair complete?

--

Go to Diagnostic System Check

--

Note the readings from the scan tool.

Is the reading equivalent to the specified value?

0V

Go to Step 15

Go to Blower Has High Speed Only

1. Turn the ignition to the OFF position.
2. Disconnect the heater and the A/C control module electrical connector.
3. Disconnect the blower motor control module electrical connector.
4. Connect a test lamp between the blower motor control module connector terminals B and C.

Does the test lamp light?

--

Go to Step 16

Go to Blower Has High Speed Only

Repair a short to ground in CKT 760.

Is the repair complete?

--

Go to Diagnostic System Check

--

Connect a test lamp between the blower motor control module harness terminals A and C.

Does the test lamp light?

--

Go to Step 18

Go to Step 19

Repair a short to battery in CKT 760.

Is the repair complete?

--

Go to Diagnostic System Check

--

Replace the blower motor control module.

Does the blower motor operate correctly?

--

Go to Diagnostic System Check

Go to Step 20

Replace the heater and the A/C control module.

Is the repair complete?

--

Go to Diagnostic System Check

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