Schematic Reference: HVAC Schematics

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

Did you perform the HVAC Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - HVAC Systems - Manual

1. Turn ON the ignition, with the engine OFF.
2. Place the mode switch in the vent position.
3. Place the blower motor switch in each speed position.

Does the blower motor operate in any speed position?

Go to Blower Motor Malfunction

Go to Step 3

1. Turn OFF the ignition.
2. Disconnect the blower motor.
3. Turn ON the ignition, with the engine OFF.
4. Connect a test lamp between the blower motor supply voltage circuit and a good ground.
5. Place the blower motor switch in the minimum speed position.

Does the test lamp illuminate?

Go to Step 4

Go to Step 6

Connect a test lamp between the blower motor supply voltage circuit and the blower motor ground circuit.

Does the test lamp illuminate?

Go to Step 14

Go to Step 5

Test the ground circuit of the blower motor resistor assembly for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 22

Go to Step 15

Turn the ignition ON and OFF.

Does the blower motor relay turn ON and OFF?

Go to Step 7

Go to Step 11

1. Turn OFF the ignition.
2. Disconnect the blower motor resistor assembly connector C1.
3. Turn ON the ignition, with the engine OFF.
4. Place the blower motor switch in the minimum speed position.
5. Connect a test lamp between the low blower motor control circuit of the blower motor resistor assembly and a good ground.

Does the test lamp illuminate?

Go to Step 15

Go to Step 8

1. Turn OFF the ignition.
2. Disconnect the HVAC control module connector C2.
3. Turn ON the ignition, with the engine OFF.
4. Connect a test lamp between the battery positive voltage circuit of the HVAC control module and a good ground.

Does the test lamp illuminate?

Go to Step 16

Go to Step 9

Test the battery positive voltage circuit of the HVAC control module for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 22

Go to Step 10

Test the battery positive voltage circuit of the blower motor relay for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 22

Go to Step 13

1. Turn OFF the ignition.
2. Disconnect the blower motor relay.
3. Turn ON the ignition, with the engine OFF.
4. Connect a test lamp between the ignition 3 voltage circuit of the blower motor relay and the ground circuit of the blower motor relay.

Does the test lamp illuminate?

Go to Step 13

Go to Step 12

Test the ignition 3 voltage circuit of the blower motor relay for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 22

Go to Step 17

Inspect for poor connections at the harness connector of the blower motor relay. 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 22

Go to Step 18

Inspect for poor connections at the harness connector of 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 22

Go to Step 19

Inspect for poor connections at the harness connector of the blower motor resistor assembly. 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 22

Go to Step 20

Inspect for poor connections at the harness connector of the HVAC control module. 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 22

Go to Step 21

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

Did you complete the repair?

Go to Step 22

--

Replace the blower motor relay.

Did you complete the replacement?

Go to Step 22

--

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

Did you complete the replacement?

Go to Step 22

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Replace the blower motor resistor assembly. Refer to Blower Motor Resistor Assembly Replacement in Heating, Ventilation and Air Conditioning.

Did you complete the replacement?

Go to Step 22

--

Replace the HVAC control module. Refer to HVAC Control Module Replacement .

Did you complete the replacement?

Go to Step 22

--

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3