3. Position the clutch fieldcoil wire lead and connec-
tor (3) to the A/C compressor (4) and install the
plastic retaining clip (1) and the screw (2) that
secures the wire lead to the compressor. Tighten
thescrewto4Nꞏm(35in.lbs.).
4. Align the pulley and bearing assembly (1) squarely
onto the front of the A/C compressor (2).
NOTE: A distinct change of sound during the
clutch pulley tapping process indicates that the
pulley and bearing assembly has bottomed out
against the compressor housing.
5. Using clutch pulley installer (Special Tool 9355 in
Kit 9349) (3) and a hammer (4), install the pulley
and bearing assembly onto the front of the A/C
compressor. Tap the installer with a hammer until
the pulley and bearing assembly has bottomed
against the compressor housing.
CAUTION: If the snap ring is not fully seated in the
groove it will vibrate out, resulting in clutch failure
and severe damage to the A/C compressor.
NOTE: Install the snap ring with the beveled side
ofthesnapringfacingoutward.
6. Using snap ring pliers (1), install the snap ring (2)
that secures the pulley and bearing assembly (3) to
the front of the A/C compressor (4). Make sure the
snap ring is properly seated in the groove.
RESISTOR-BLOWER MOTOR
DESCRIPTION
The blower motor resistor is mounted to the bottom of
the HVAC housing, directly behind the glove box. The
blower motor resistor consists of a molded plastic
mounting plate (1) with an integral wire connector
receptacle (2). Concealed behind the mounting plate
are coiled resistor wires contained within a ceramic
heat sink (3).
OPERATION
The blower motor resistor is connected to the vehicle electrical system through a dedicated wire lead and connector
of the HVAC wire harness. The blower motor resistor has multiple resistor wires, each of which will reduce the
current flow through the blower motor to change the blower motor speed.
The blower motor control for the heating-A/C system directs the ground path for the blower motor through the cor-
rect resistor wire to obtain the selected speed. With the blower motor control in the lowest speed position, the
ground path for the blower motor is applied through all of the resistor wires. Each higher speed selected with the
blower motor control applies the blower motor ground path through fewer ofthe resistor wires, increasing the blower
motor speed.
The blower motor resistor cannot be adjusted or repaired and, if faulty or damaged, it must be replaced.
DIAGNOSIS AND TESTING
BLOWER MOTOR RESISTOR
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
negative battery (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 accidental airbag deploymentand possible personal injury or
death.
NOTE: For circuit descriptions and diagrams, refer to the appropriate wiring information. The wiring infor-
mation includes wiring diagrams, proper wire and connector repair procedures, further details on wire har-
ness routing and retention, as well as pin-out and location views for the various wire harness connectors,
splices and grounds.
1. Disconnect and isolate the negative battery cable.
2. Disconnect the wire harness connector from the blower motor resistor (Refer to 24 - HEATING & AIR CONDI-
TIONING/CONTROLS/RESISTOR-BLOWER MOTOR - REMOVAL).
SENSOR-EVAPORATOR TEMPERATURE
DESCRIPTION
The evaporator temperature sensor is a two-wire tem-
perature sensing element located at the coldest point
on the face of the A/C evaporator. The probe (1) for
evaporator temperature sensor is attached to the
evaporator coil fins. The wire lead (2) for evaporator
temperature sensor is routed through an opening at
the back of the HVAC housing and the connector (3)
is attached to the HVAC wire harness.
OPERATION
The evaporator temperature sensor monitors the surface temperature of A/C evaporator and supplies an input signal
to the A/C-heater control. The A/C-heater control uses the evaporator temperature sensor input signal to optimize
A/C system performance and to protect the A/C system from evaporator freezing. The evaporator temperature sen-
sor will change its internal resistance in response to the temperatures itmonitors and is connected to the A/C-heater
control through sensor ground circuit and a 5-volt reference signal circuit. As the temperature of the A/C evaporator
decreases, the internal resistance of the evaporator temperature sensordecreases.
The A/C-heater control uses the monitored voltage reading as an indication of evaporator temperature. The A/C-
heater control is programmed to respond to this input by requesting the powertrain control module (PCM) or the
engine control module (ECM) (depending on engine application) to cycle the A/C compressor clutch as necessary to
optimize A/C system performance and to protect the A/C system from evaporatorfreezing(Referto24-HEATING
& AIR CONDITIONING/CONTROLS/COIL-A/C COMPRESSOR CLUTCH - OPERATION formore information).
The evaporator temperature sensor is diagnosed using a scan tool (Refer to24 - HEATING & AIR CONDITIONING
- DIAGNOSIS AND TESTING and to 24 - HVAC Electrical Diagnostics for more information).
The evaporator temperature sensor cannot be adjusted or repaired and, if faulty or damaged, it must be replaced.
