Test O: The Blower Motor Does Not Operate Correctly - Manual Climate Control

PINPOINT TEST O: THE BLOWER MOTOR DOES NOT OPERATE CORRECTLY - MANUAL CLIMATE CONTROL

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Normal Operation
Under normal operation, when the high speed blower relay is not energized, the blower motor is provided a ground from the resistor through circuit CH446 (BU/BN)/VH301 (YE/BU). The resistor gets a ground from circuit GD140 (BK/GN) in the lowest blower setting. In MED-LO and MED-HI, the resistor gets a ground through circuit CH428 (GN/WH) or CH429 (GY/BN), depending on selected speed. The blower switch receives its ground from circuit GD138 (BK/WH).

The high speed blower motor relay coil receives voltage through circuit CH402 (YE/GN) from the blower motor relay. The coil receives ground from the function selector switch through circuit CH430 (VT/OG) when the highest blower speed is selected. Ground for high blower speed is provided to the high speed blower relay through circuit GD140 (BK/GN) when the relay is energized. The high speed blower motor relay provides the blower motor ground through circuit VH301 (YE/BU).

Possible Causes
- An open in circuit GD138 (BK/WH), GD140 (BK/GN), CH430 (VT/OG), CH402 (YE/GN), CH428 (GN/WH) or CH429 (GY/BN)
- A short to ground in circuit CH430 (VT/OG), CH446 (BU/BN), CH428 (GN/WH) or CH429 (GY/BN)
- A short together circuits CH446 (BU/BN), CH428 (GN/WH) or CH429 (GY/BN)
- Blower motor resistor
- Blower motor switch
- High speed blower motor relay