Blower Motor: Testing and Inspection

BLOWER MOTOR (Manual A/C)





1. Check for bending or abnormal deflection of the rotating shaft of the blower motor assembly.
2. Check for cracking or deterioration of the packing.
3. Check for damage to the fan.
4. Check for damage to the blower case.
5. Check the operation of the inside/outside air selection damper, and for damage.





6. Connect the blower motor terminals directly to the battery and check that the blower motor operates smoothly.
7. Next, reverse the polarity and check that the blower motor operates smoothly in the reverse direction.

MOTOR VOLTAGE UP TO FAN SPEED (AUTO A/C)











Auto A/C control module controls the blower motor speed by shifting the base voltage of Power Transistor

Power Transistor





1. Measure voltage between pin 1 and pin 2.
2. The voltage increases up to selecting blower motor speed button until Hi-blower relay works.