SCHEMATIC REFERENCES: HVAC Blower Control Schematics

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 HVAC control in the VENT position.
3. Place the blower motor switch in each position (1, 2, 3 and 4).

Does the blower motor operate in all speeds?

Go to Symptoms - HVAC Systems - Manual

Go to Step 3

Does the blower motor operate in high speed regardless of the blower motor switch position?

Go to Step 4

Go to Step 5

Test the high (position 4) blower motor circuit for a short to ground. Refer to Circuit Testing in Wiring Systems.

Did you find and correct the condition?

Go to Step 8

Go to Step 6

Test the high (position 4) blower motor circuit for an open between the blower motor resister and the splice.

Did you find and correct the condition?

Go to Step 8

Go to Step 7

Replace the HVAC control head. Refer to HVAC Module Assembly Replacement in Heating, Ventilation and Air Conditioning.

Did you complete the replacement?

Go to Step 8

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

Is the repair complete?

Go to Step 8

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Operate the vehicle in order to verify the repair.

Is the repair complete?

System OK

Go to Step 2