Schematic Reference: HVAC Schematics

DEFINITION: The blower motor operates in at least one, but not 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 any position except OFF.
3. Place the blower motor switch in each speed position.

Does the blower motor operate at the desired speeds?

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 resistor assembly.
3. Turn ON the ignition, with the engine OFF.
4. Probe the LOW, MED 1, MED 2, and HIGH blower motor control circuits at the blower motor resistor assembly, with a test lamp that is connected to battery positive voltage. At the same time, place the blower motor switch in the appropriate speed position for the circuit being tested.

Does the test lamp illuminate on all blower motor control circuits?

Go to Step 5

Go to Step 4

Test the applicable blower motor control circuit 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 10

Go to Step 7

Test each blower motor 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 10

Go to Step 6

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 10

Go to Step 8

Inspect for poor connections at the harness connector of the HVAC control 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 10

Go to Step 9

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

Did you complete the replacement?

Go to Step 10

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Replace the HVAC control assembly. Refer to Heater and Air Conditioning Control Replacement .

Did you complete the replacement?

Go to Step 10

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Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2