Chrysler Le Baron, Dodge Dynasty, Plymouth Acclaim. Manual - part 202

To install, reverse the preceding operation.

BLEND-AIR DOOR ACTUATOR

The blend-air door actuator (Fig. 10) is an electric

servo motor which mechanically positions the A/C
unit temperature door. Actuation of the servo motor
will occur when drive signals are supplied to the ac-
tuator from the computer control. A feedback strip in
the actuator allows the computer control to know the
exact position of the temperature door at all times.
The blend-air door actuator is not serviceable and
must be replaced if found to be defective.

CAUTION: Do not remove any of the motor actua-
tors from the heater-A/C unit assembly with any
electrical power applied. Removal should only be
done with the Ignition OFF. The actuators have no
mechanical stops to limit their travel. If the actuator
rotates and is not connected to the unit assembly,
it will become un-calibrated.

REMOVAL AND INSTALLATION

The blend-air door actuator is located on the A/C-

heater housing above the floor hump.

(1) Remove under panel silencers.
(2) Remove the carpeted cover over the air bag

control module.

(3) Remove floor air distribution duct.
(4) Locate and remove three actuator attaching

screws.

(5) Lower the blend-air door actuator from A/C-

heater housing while removing actuator from blend-
air door shaft (Fig. 11).

(6) Disengage wire connector lock and unplug con-

nector.

To install, reverse the preceding operation.

CAUTION: Align the blend-air door shaft to the slot
in the actuator. Be sure the shaft on blend-air door
actuator is properly engaged (when installing) to
prevent damage.

Perform system check.

MODE DOOR ACTUATOR

The mode door actuator is an electric servo motor.

It (with the use of linkages) mechanically positions
the A/C unit panel/bi-level door and the floor/defrost
door. Actuation of the servo motor will occur when
drive signals are supplied to the actuator from the
computer control. This actuator also contains a feed-
back strip which allows the computer control to know
the exact position of the mode door at all times. The
mode door actuator is not serviceable and must be re-
placed if found to be defective.

The Mode Door Actuator is located on the side of

the A/C-heater case near the accelerator pedal.

REMOVAL AND INSTALLATION

(1) Remove under panel silencer.
(2) Disconnect electrical connector from actuator.
(3) Pinch and remove the lower plastic clip from

the actuator arm (Fig. 12).

Fig. 10 Blend-Air Door Actuator—Mode Door

Actuator—View from bottom of A/C Housing

Figs. 11 Blend-Air Door Actuator Removal and

Installation—View from bottom of A/C Housing

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(4) Remove the three actuator bracket mounting

screws (Fig. 13).

(5) Rotate actuator to gain access to upper plastic

clip. Pinch and remove the upper plastic clip from
the actuator arm.

(6) Remove actuator-to-actuator mounting bracket

screws.

(7) Remove actuator from mounting bracket. Re-

move from vehicle.

To install, reverse the preceding operation.

IN-CAR TEMPERATURE SENSOR/ASPIRATOR
ASSEMBLY

The ATC system uses various sensors which return

electrical signals to the computer control. The in-car
temperature sensor is part of a motorized aspirator
assembly (Fig. 14) that is mounted in the instrument
panel. A small fan (in the aspirator) draws air
through an intake on the instrument panel. This air
flows over a thermistor which picks up temperature
variations. The computer control then makes system
adjustments to maintain a constant passenger com-

partment temperature. The in-car temperature sen-
sor/aspirator assembly is not serviceable and must be
replaced if found to be defective.

The In-Car Temperature Sensor/Aspirator Assem-

bly is located behind the instrument panel and to the
right of the steering column. The air intake opening
for the aspirator is located to the right of the steer-
ing column (Fig. 15). The Sensor and Aspirator are
wired together and must be replaced as an assembly.

REMOVAL AND INSTALLATION

(1) Remove the instrument cluster assembly. Refer

to Cluster and Gauge Service section in Group 8E.

(2) Un-snap the sensor from the instrument panel

(Fig. 16).

Fig. 12 Plastic Clip on Mode Door Actuator

Fig. 13 Actuator Bracket Mounting Screws

Fig. 14 In-car Temperature Sensor/Aspirator

Assembly

Fig. 15 Aspirator Air Intake

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HEATING AND AIR CONDITIONING

(3) Remove the two aspirator mounting screws.
(4) Disconnect the aspirator intake hose from the

instrument panel.

(5) Remove sensor/aspirator and it’s wiring har-

ness from vehicle.

To install, reverse the preceding operation.

WATER TEMPERATURE SENSOR

The water temperature sensor is located on the

heater core mounting plate (Fig. 17). This is a ther-
mistor which will pick up on the engines coolant
temperature. The computer control uses this informa-
tion to control the cold engine lockout time. The wa-
ter temperature sensor is not serviceable and must
be replaced if found to be defective.

The Water Temperature Sensor is located on the

heater hose mounting plate between the heater hose
nipples.

REMOVAL AND INSTALLATION

(1) The A/C-heater housing assembly must be re-

moved for Water Temperature Sensor replacement.
Refer to Heater-A/C Unit Housing Removal and In-
stallation—AC/AY Body for procedures.

(2) Remove sensor mounting screw (Fig. 18).

(3) Disconnect the sensor pigtail wiring harness

from the main wiring harness and remove sensor
from vehicle.

To install, reverse the preceding operation. When

tightening the sensor mounting screw, allow the sen-
sor to rotate and contact the upper heater hose nip-
ple. This will aid in sensor efficiency.

SUN SENSOR

The sun sensor (Fig. 19) is mounted on the driver

side of the vehicle on top of the instrument panel.
This is not a thermistor type sensor but rather a
photo diode. For this reason the sun sensor responds
to sun light intensity rather than temperature. It is
used to aid in determining proper mode door position.
The sun sensor is not serviceable and must be re-
placed if found to be defective.

REMOVAL AND INSTALLATION

(1) Carefully pry up the sensor from the instru-

ment panel with a screwdriver (Fig. 20). Place a rag
under the screwdriver to prevent scratching of the
instrument panel.

(2) Disconnect the sensor at the wiring harness.
To install, reverse the preceding operation. Snap

the sensor securely to the instrument panel.

Fig. 16 In-Car Temperature Sensor/Aspirator

Assembly Removal and Installation

Fig. 17 Water Temperature Sensor

Fig. 18 Water Temperature Sensor Removal and

Installation

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NON—COMPUTER AIDED DIAGNOSTIC TESTS

Determine whether the operator complaint is due

to a system failure or improper operation of the ATC
system. The system will to go into a maximum heat
or cooling mode if the operator changes the tempera-
ture setting four or more degrees.

Check the following:

• Coolant level

• Refrigerant charge

• Drive belt tension

• Radiator air flow

• Radiator fan operation

• Air suction of In-car Temperature Sensor/Aspirator

To check air suction of the Aspirator, place a small

piece of tissue paper over the Aspirator opening on
the instrument panel. This opening is located to the
right of the steering column. The tissue paper should
cling to the opening if system is functioning properly.

Bring the engine to normal operating temperature

and proceed with Computer Aided Diagnostic Proce-
dures. Always test the entire system after each re-
pair has been performed.

COMPUTER AIDED DIAGNOSTIC TESTS

The ATC control has a computer capable of trou-

bleshooting the entire ATC system in approximately
60 seconds. The engine must be running and at nor-
mal operating temperature during the test to provide
hot coolant for the heater.

During the ATC Diagnostic Test, the computer will

calibrate the Mode and Blend Door actuators.

CAUTION: Do not remove the actuators from the
heater-A/C unit assembly with power applied. Re-
moval should only be done with the Ignition OFF.
The actuators have no mechanical stops to limit the
travel. If the actuator rotates and is not connected
to the unit assembly, it will become un-calibrated.

The Diagnostic Test is capable of checking all elec-

trical signals between the ATC Control Module, ac-
tuators, sensors and blower control.

The Diagnostic Test will display two types of Diag-

nostic trouble Codes (Fig. 21). The Diagnostic Trou-
ble Codes numbered 01 through 22, have been
detected during the Diagnostic Test. Diagnostic Trou-
ble Codes numbered 23 through 28, have been de-
tected during normal ATC operation. Diagnostic
Trouble Codes 23 through 28 would then be stored in
the ATC control computer and are only being re-
trieved during the Diagnostic Test.

For electrical pin numbers, refer to the wiring Pin

out charts on the following pages in this section.

(1) Start vehicle and allow engine to warm up.
(2) For

two

seconds,

depress

the

DEFROST,

FLOOR and MODE buttons at the same time. The
ATC control should begin to flash on and off.

(3) During the Diagnostic Test perform the follow-

ing symptom tests:

(a) Do all display symbols and indicators illumi-

nate ?

Fig. 19 Sun Sensor

Fig. 20 Sun Sensor Removal

Fig. 21 Automatic Temperature Control Diagnostic

Trouble Codes

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