Dodge ZB 2005 Service Manual page 1056

ZB
BLOWER MOTOR
DESCRIPTION
The blower motor (Fig. 2) is a 12-volt, direct cur-
rent (DC) motor mounted within a plastic housing
with an integral wire connector and squirrel cage-
type blower wheel that is secured to the blower
motor shaft. The blower motor wheel is located in the
HVAC air inlet housing which is mounted to the pas-
senger side end of the HVAC housing.
The blower motor can be accessed for service from
underneath the instrument panel.
Fig. 2 Blower Motor - Typical
1 - BLOWER MOTOR
2 - BLOWER WHEEL
3 - MOTOR SHAFT
OPERATION
The blower motor is used to control the velocity of
air moving through the HVAC housing by spinning
the blower wheel within the HVAC air inlet housing
at the selected speed.
The blower motor will operate whenever the igni-
tion switch is in the On position and the blower
motor control in any position except Off. Blower
motor speed is controlled by regulating the path to
ground through the blower motor resistor and
through the blower motor control located within the
A/C-heater control.
The blower motor and blower motor wheel are fac-
tory balanced and cannot be adjusted or repaired. If
faulty or damaged, the blower motor and blower
wheel must be replaced as an assembly.
DIAGNOSIS AND TESTING
BLOWER MOTOR
WARNING: On vehicles equipped with airbags, dis-
able the airbag system before attempting any steer-
ing wheel, steering column, or instrument panel
component diagnosis or service. Disconnect and
isolate the negative battery (ground) cable, then
wait two minutes for the airbag system capacitor to
discharge before performing further diagnosis or
service. Failure to take the proper precautions
could result in accidental airbag deployment and
possible personal injury or death.
NOTE: For circuit descriptions and diagrams, refer
to Air Conditioning/Heater in Group 8W - Wiring
Diagrams.
OPERATION
Possible causes of an inoperative blower motor or
blower motor not operating in all speeds include:
• Faulty fuse
• Faulty blower motor resistor
• Faulty blower motor switch
• Faulty blower motor
• Faulty blower motor circuit wiring or wire har-
ness connectors
Possible causes of the
VIBRATION
Possible causes of blower motor vibration include:
• Improper blower motor mounting
• Improper blower wheel mounting
• Deformed blower wheel
• Out of balance blower wheel due to foreign
material in the wheel
• Faulty blower motor
NOISE
To determine if the blower motor is the source of
the noise, simply switch the blower motor from Off to
On. To verify that the blower motor is the source of
the noise, unplug the blower motor wire harness con-
nector and operate the heating-A/C system. If the
noise goes away, possible causes include:
• Foreign material in the HVAC air inlet housing
• Improper blower motor mounting
• Improper blower wheel mounting
• Faulty blower motor
DISTRIBUTION 24 - 27