Schematic Reference: HVAC Schematics

DEFINITION: The blower motor is ON while the blower motor switch is in the OFF position.

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 the OFF position.

Is the blower motor OFF?

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

Go to Step 3

1. Turn OFF the ignition.
2. Disconnect the blower motor 1 relay.
3. Turn ON the ignition, with the engine OFF.

Is the blower motor OFF?

Go to Step 5

Go to Step 4

1. Turn OFF the ignition.
2. Disconnect the blower motor resistor assembly.
3. Turn ON the ignition, with the engine OFF.

Is the blower motor OFF?

Go to Step 11

Go to Step  13

1. Turn OFF the ignition.
2. Disconnect the blower motor switch.
3. Connect a test lamp between battery voltage and each control circuit.

Does the test lamp illuminate at any control circuit?

Go to Step 7

Go to Step 6

1. Turn OFF the ignition.
2. Reconnect the blower motor resistor assembly, blower motor switch or HVAC control module and blower motor 1 relay.
3. Turn ON the ignition, with the engine OFF.

Is the blower motor operating in high speed?

Go to Step 9

Go to Step 8

Test the appropriate blower motor speed control circuit for a 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 10

Inspect for poor connections at the harness connector of the blower motor 1 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 harness connector of the blower motor 2 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 15

Inspect for poor connections at the harness connector of the HVAC control module or blower motor switch if not equipt with 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 17

Go to Step 16

Test the blower motor resistor supply voltage circuit for a short to voltage. 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 12

Repair the short to voltage in the medium blower motor supply circuit between the blower motor resistor assembly and the blower motor 2 relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 17

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Repair the short to voltage in the blower motor supply voltage circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 17

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Replace the blower motor 1 relay.

Did you complete the replacement?

Go to Step 17

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Replace the blower motor 2 relay.

Did you complete the replacement?

Go to Step 17

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Replace the HVAC control module or blower motor switch if not equipt with A/C. Refer to HVAC Control Module Replacement or Blower Motor Switch 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