Schematic Reference: HVAC Schematics

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

Did you review the HVAC operation and perform the necessary inspections?

Go to Step 2

Go to Symptoms - HVAC Systems - Manual

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

Is the auxiliary blower motor inoperative in all speed positions?

Go to Step 4

Go to Step 3

1. Turn ON the headlamps.
2. Place the instrument panel dimmer switch in the brightest position.
3. Place the front auxiliary blower motor switch in each speed position.

Is the auxiliary blower motor inoperative in all speed positions?

Go to Step 9

Go to Auxiliary Blower Motor Malfunction

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

Does the test lamp illuminate?

Go to Step 5

Go to Step 6

1. Connect a test lamp between the auxiliary blower motor supply voltage circuit and the auxiliary blower motor ground circuit.
2. Place the front auxiliary blower motor switch in the maximum speed position.

Does the test lamp illuminate?

Go to Step 10

Go to Step 12

Test the auxiliary blower motor supply voltage circuit for an open, high resistance or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 7

Test the ignition 3 voltage circuit to the auxiliary blower motor relays for an open, high resistance or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 8

Test the battery positive voltage circuit to the auxiliary blower motor relays for an open, high resistance or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 9

Test the ground circuit of the auxiliary blower motor switch (auxiliary heat only) or front auxiliary HVAC control assembly (auxiliary heat and A/C) 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 15

Go to Step 11

Inspect for poor connections at the harness connector of the auxiliary 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 15

Go to Step 13

Inspect for poor connections at the harness connector of the auxiliary blower motor switch (auxiliary heat only) or front auxiliary HVAC control assembly (auxiliary heat and A/C). 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 15

Go to Step 14

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

Did you complete the repair?

Go to Step 15

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

Did you complete the replacement?

Go to Step 15

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Replace the auxiliary blower motor switch (auxiliary heat only) or the front auxiliary HVAC control assembly (auxiliary heat and A/C). Refer to Auxiliary Blower Motor Switch Replacement or Auxiliary Heater and Air Conditioning Control Replacement - Front .

Did you complete the repair?

Go to Step 15

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Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2