Blower Motor Resistor; Blower Motor Power Module; Compressor - Chrysler 2000 LHS Owner's Manual

24 - 2 HEATING AND AIR CONDITIONING
DESCRIPTION AND OPERATION (Continued)
changes resistance with air temperature. The BCM
measures this resistance and calculates the tempera-
ture of the air drawn into the ATC Control. The ATC
system then makes adjustments to maintain the opti-
mum passenger compartment comfort. Refer to the
ATC Sensor Motor-Fan Operation table for when the
ATC Sensor is operating.
Fig. 1 ATC In-Car Temperature Sensor
1 – ATC IN-CAR TEMPERATURE SENSOR
OPERATION
ATC SENSOR MOTOR-FAN OPERATION
CONDITION
IGNITION SWITCH IS
ON.
VEHICLE IS DRIVEN,
THEN THE IGNITION
SWITCH IS TURNED
OFF.
VEHICLE DOOR IS
OPENED WITHOUT
TURNING ON THE
IGNITION SWITCH AND
LEFT OPEN.
VEHICLE DOOR IS
OPENED AND THEN
CLOSED WITHOUT
TURNING ON THE
IGNITION SWITCH.
The in-car sensor motor is an integral part of the
Control Head and not a separate serviceable part.
The ATC Control Head must be replaced if there is a
fault relating to the motor. See Diagnosis and Testing
in this section for proper check of airflow. The In-Car
Sensor Thermistor is part of the ATC Control Head
and not a separate serviceable part. One must
replace the ATC Control Head if the ATC self-diag-
nostics indicates a fault code. See Self-Diagnostics in
ATC SENSOR MOTOR
OPERATION
MOTOR ALWAYS
OPERATES, EVEN
WHEN ATC CONTROL
HEAD "OFF BUTTON IS
PUSHED.
MOTOR TURNS OFF
WHEN THE IGNITION
SWITCH IS TURNED
OFF.
MOTOR TURNS OFF IN
APPROXIMATELY 2
MINUTES AFTER DOOR
IS OPENED.
MOTOR TURNS OFF IN
APPROXIMATELY 2
MINUTES AFTER DOOR
IS SHUT.
this section for information on diagnosing wiring and
thermistor.

BLOWER MOTOR RESISTOR

DESCRIPTION
Vehicles with manual air conditioning (non-ATC)
systems will have a blower motor resistor. The resis-
tor is mounted to the lower right side of the heater-
A/C housing in the passenger compartment, where it
can be accessed for service. See Blower Motor Resis-
tor in the Removal and Installation section of this
group for more information.
The blower motor resistor has multiple resistor
wires, each of which will change the resistance in the
blower motor ground path to change the blower
motor speed. The blower motor switch directs the
ground path through the correct resistor wire to
obtain the selected blower motor speed.
The blower motor resistor cannot be repaired and,
if faulty or damaged, it must be replaced.
OPERATION
With the blower motor switch in the lowest speed
position the ground path for the motor is applied
through all of the resistor wires. Each higher speed
selected with the blower motor switch applies the
blower motor ground path through fewer of the resis-
tor wires, increasing the blower motor speed. When
the blower motor switch is in the highest speed posi-
tion, the blower motor resistor is bypassed and the
blower motor receives a direct path to ground.

BLOWER MOTOR POWER MODULE

DESCRIPTION
The blower motor power module is only used in
vehicles equipped with Automatic Temperature Con-
trol (ATC). It is located on the lower right side of the
HVAC unit housing, and is controlled by the Body
Control Module (BCM).
OPERATION
The power module receives pulse width modulated
(PWM) signals from the BCM. The power module
varies voltage to the blower motor for different
blower speeds based on the ATC software. There are
14 selectable speeds, while the Auto mode provides
256 variations.

COMPRESSOR

DESCRIPTION
The air conditioning system uses a Nippondenso
10PA17 ten cylinder, double-acting swash plate-type
compressor on all models. This compressor has a
LH