Schematic Reference: HVAC Schematics

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

1

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 blower motor switch in each speed position.

Does the blower motor operate in any of speed positions?

Go to Blower Motor Malfunction in Wiring Systems

Go to Step 3

1. Turn OFF the ignition.
2. Disconnect the blower motor.
3. Turn ON the ignition, with the engine OFF.
4. Probe the blower motor supply voltage circuit of the blower motor with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 4

Go to Step 7

Connect a test lamp between the blower motor supply voltage circuit and the high blower motor control circuit of the blower motor.

Does the test lamp illuminate?

Go to Step 11

Go to Step 5

Test the high blower motor control circuit for an open or high resistance between the blower motor and the splice. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 17

Go to Step 6

Test the blower motor switch ground 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 17

Go to Step 12

7

Test the blower motor supply voltage circuit of the blower motor 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 17

Go to Step 8

Probe the blower motor relay ignition 3 voltage circuit with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 9

Go to Step 13

Test the ground 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 17

Go to Step 10

Inspect for poor connections at 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 17

Go to Step 14

Inspect for poor connections at 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 17

Go to Step 15

Inspect for poor connections at 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 17

Go to Step 16

Repair the ignition 3 voltage circuit of the blower motor relay. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 17

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

Did you complete the replacement?

Go to Step 17

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

Did you complete the replacement?

Go to Step 17

--

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

Did you complete the replacement?

Go to Step 17

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Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2