Schematic Reference: HVAC Schematics

DEFINITION: The blower motor is inoperative in all speed positions.

Did you perform the HVAC Systems Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check - HVAC Systems - Automatic

1. Turn ON the ignition, with the engine OFF.
2. Place the blower motor switch in any speed position.

Does the blower motor operate?

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

Go to Step 3

Inspect the HEATER BLOWER fuse.

Is the fuse open?

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Go to Step 4

Go to Step 5

Test the battery feed circuit A465 to the blower control module for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 21

Go to Step 6

Remove the HEATER BLOWER fuse and test for voltage at the fuse block terminal that is hot at all times.

Is the voltage within the specified value?

11-13 V

Go to Step 7

Go to Step 8

The short to ground may be intermittent at this time. Refer to Inducing Intermittent Fault Conditions in Wiring Systems. Replace the HEATER BLOWER fuse.

Did you replace the fuse?

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Go to Step 21

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1. Install the HEATER BLOWER fuse.
2. Disconnect the blower control module.
3. Connect the negative lead of the DMM to terminal 3 of the blower control module connector.
4. With the positive lead, measure the voltage at terminal 1 of the blower control module connector.

Is the voltage within the specified value?

11-13 V

Go to Step 9

Go to Step 10

Test the HEATER BLOWER fuse battery feed circuit A60 for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 21

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1. Connect the blower control module.
2. Measure the voltage at terminal 6 (motor +).

Is the voltage within the specified value?

11-13 V

Go to Step 11

Go to Step 13

1. Move the negative lead of the DMM to another ground location.
2. Measure the voltage at terminal 1.

Is the voltage within the specified value?

11-13 V

Go to Step 17

Go to Step 18

1. Disconnect the BRN blower motor ground circuit from the blower control module.
2. Connect a 30A fused jumper wire between the BRN wire and a good ground.
3. Turn ON the ignition, with the engine OFF.

Does the blower motor operate?

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Go to Step 12

Go to Step 20

Test for an open or a short to ground in CKT FP812. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 21

Go to Step 14

Measure the voltage on the blower speed output at the heater and A/C control.

Does the voltage measure near the specified value?

Go to Step 14

Go to Step 15

Inspect for poor connections at the harness connector of the blower control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 21

Go to Step 16

Inspect for poor connections at the harness connector of the heater and A/C control. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 21

Go to Step 19

Replace the blower control module. Refer to Blower Motor Control Module Replacement .

Did you complete the replacement?

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Go to Step 21

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Locate and repair the open in CKT F812 (BLK). Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 21

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Locate and repair the open in CKT A465 (RED). Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 21

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Important: Perform the set up procedure for the heater and A/C control.

Replace the heater and A/C control. Refer to HVAC Control Module Replacement .

Did you complete the replacement?

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Go to Step 21

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Replace the blower motor. Refer to Blower Motor Replacement in Heating Ventilation and Air Conditioning.

Did you complete the replacement?

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Go to Step 21

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Operate the system in order to verify the repair.

Did you correct the condition?

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System OK

Go to Step 2