Grand Cherokee 4WD V8-4.7L (2003)
Blower Motor: Testing and Inspection
WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS, DISABLE THE AIRBAG SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. DISCONNECT AND ISOLATE
THE BATTERY NEGATIVE (GROUND) CABLE, THEN WAIT TWO MINUTES FOR THE AIRBAG SYSTEM CAPACITOR TO
DISCHARGE BEFORE PERFORMING FURTHER DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE WAY TO DISABLE THE
AIRBAG SYSTEM. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN AN ACCIDENTAL AIRBAG
DEPLOYMENT AND POSSIBLE PERSONAL INJURY.
For circuit descriptions and diagrams, refer to the appropriate wiring information. Possible causes of an inoperative blower motor include:
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Faulty fuse
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Faulty blower motor circuit wiring or wire harness connections
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Faulty blower motor resistor (if the vehicle is so equipped)
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Faulty blower motor controller (if the vehicle is so equipped)
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Faulty blower motor switch
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Faulty a/c heater mode control switch
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Faulty blower motor.
Possible causes of the blower motor not operating in all speeds include:
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Faulty fuse
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Faulty blower motor switch
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Faulty blower motor resistor (if the vehicle is so equipped)
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Faulty blower motor controller (if the vehicle is so equipped)
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Faulty AZC module (if the vehicle is so equipped)
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Faulty blower motor circuit wiring or wire harness connections.
Vibration
Possible causes of blower motor vibration include:
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Improper blower motor mounting
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Improper blower wheel mounting
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Blower wheel out of balance or bent
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Blower motor faulty.
Noise
To verify that the blower is the source of the noise, unplug the blower motor wire harness connector and operate the HVAC system. If the noise goes
away, possible causes include:
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Foreign material in the HVAC housing
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Improper blower motor mounting
-
Improper blower wheel mounting
-
Blower motor faulty.
