Front Blower Motor Circuit
Front Blower Motor CircuitSYMPTOM:
- Blower motor operation is malfunctioning.
Inspection Flow:
INSPECTION FLOW
SYSTEM DESCRIPTION
Component Parts
Blower speed control system components are:
- Front air control
- Front blower motor resistor
- Front blower motor
- Front blower motor relay
System Operation
COMPONENT DESCRIPTION
Blower Motor Resistor
The front blower motor resistor is located on the cooling unit. The front blower motor resistor grounds the front blower motor through a series of 1, 2 or three resistors, depending upon speed selected. For high speed operation the front blower motor resistor is circumvented and the front blower motor grounds directly.
Diagnostic Procedure For Blower Motor (Steps 1 - 2):
Diagnostic Procedure For Blower Motor (Steps 3 - 6):
Diagnostic Procedure For Blower Motor (Steps 7 - 11):
Diagnostic Procedure For Blower Motor (Steps 12 - 16):
DIAGNOSTIC PROCEDURE FOR BLOWER MOTOR
SYMPTOM: Blower motor operation is malfunctioning under starting blower speed control.
COMPONENT INSPECTION
Front Blower Motor Relay
Check continuity between terminals by supplying 12 volts and ground to coil side terminals of relay.
Front Blower Motor
Confirm smooth rotation of the blower motor.
- Ensure that there are no foreign particles inside the blower unit.
- Apply 12 volts to terminal 2 and ground to terminal 1 and verify that the motor operates freely and quietly.
Front Blower Switch
Check continuity between terminals at each switch position.
Blower Motor Resistor
Check continuity between terminals. There will be resistance, but there should not be an open or short between any two terminals.