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Home >> Ford >> 2007 >> Focus L4-2.3L VIN Z >> Repair and Diagnosis >> Heating and Air Conditioning >> Testing and Inspection >> Pinpoint Tests >> Test B: The Blower Motor Does Not Operate Correctly
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Test B: The Blower Motor Does Not Operate Correctly

PINPOINT TEST B: THE BLOWER MOTOR DOES NOT OPERATE CORRECTLY


B1-B3:






B3-B4:






Normal Operation
Under normal operation, the blower motor receives ground from the blower motor switch or resistor through circuit 31S-FA18 (BK/RD)/31S-FA33 (BK/OG). When the blower motor switch is in the HIGH position, the blower motor is grounded through the switch. When the blower motor switch is in the LOW, MED-LOW or MED-HIGH position, the blower motor resistor is grounded by the switch through circuit 31S-FA30 (BK/WH), 31S-FA31 (BK/YE) or 31S-FA32 (BK/BU) respectively.

Possible Causes
- An open in circuit 31S-FA33 (BK/OG), 31S-FA30 (BK/WH), 31S-FA31 (BK/YE) or 31S-FA32 (BK/BU)
- A short together in circuits 31S-FA30 (BK/WH), 31S-FA31 (BK/YE) or 31S-FA32 (BK/BU)
- A short to ground in circuit 31S-FA33 (BK/OG), 31S-FA30 (BK/WH), 31S-FA31 (BK/YE) or 31S-FA32 (BK/BU)
- Blower motor switch
- Blower motor resistor.
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