Chrysler Stratus Convertible. Manual - part 151

HEATING AND AIR CONDITIONING

TABLE OF CONTENTS

page

DESCRIPTION AND OPERATION

DIAGNOSIS AND TESTING

A/C PERFORMANCE TEST . . . . . . . . . . . . . . . . . . 6
COMPRESSOR CLUTCH COIL . . . . . . . . . . . . . . . 7
COMPRESSOR NOISE TEST. . . . . . . . . . . . . . . . . 7
CONTROL MODULE . . . . . . . . . . . . . . . . . . . . . . . 7
HEATER PERFORMANCE TEST . . . . . . . . . . . . . . 7
SYSTEM OIL LEVEL . . . . . . . . . . . . . . . . . . . . . . . 8
THERMAL LIMITER SWITCH . . . . . . . . . . . . . . . . 9

SERVICE PROCEDURES

EVACUATING REFRIGERANT SYSTEM. . . . . . . . . 9
R-134a REFRIGERANT . . . . . . . . . . . . . . . . . . . . 10
SYSTEM CHARGE LEVEL . . . . . . . . . . . . . . . . . . 11
SYSTEM LEAK CHECKING . . . . . . . . . . . . . . . . . 12
THERMOCOUPLE PROBE . . . . . . . . . . . . . . . . . . 12

REMOVAL AND INSTALLATION

DISASSEMBLY AND ASSEMBLY

UNIT HOUSING RECONDITION . . . . . . . . . . . . . 33

SPECIFICATIONS

A/C APPLICATION TABLE . . . . . . . . . . . . . . . . . . 40
COMPRESSOR . . . . . . . . . . . . . . . . . . . . . . . . . . 40
CLUTCH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
THERMAL LIMITER SWITCH . . . . . . . . . . . . . . . 41

SPECIAL TOOLS

AIR CONDITIONING . . . . . . . . . . . . . . . . . . . . . . 41

HEATING AND AIR CONDITIONING

24 - 1

DESCRIPTION AND OPERATION

A/C PRESSURE TRANSDUCER

DESCRIPTION

The a/c pressure transducer is located on the dis-

charge line near the compressor, and functions as the
refrigerant system pressure sensor. This switch pre-
vents compressor operation when the discharge line
pressure approaches extreme levels.

The a/c pressure transducer is a factory-calibrated

unit. The switch cannot be adjusted or repaired, and
if faulty or damaged, it must be replaced.

OPERATION

When the discharge line pressure rises above 2971

kPa (431 psi) the switch contacts open and interrupt
the A/C clutch relay signal from the PCM. The switch
also opens when the pressure drops below 206 kPa
(30 psi). The PCM responds by de-energizing the
compressor clutch relay, which will disengage the
compressor clutch.

A/C REFRIGERANT LINES

DESCRIPTION

The air conditioning lines used on this vehicle are

made from reinforced rubber with a nylon liner on
the inner walls. The ends of the A/C lines are made
with light weight aluminum fittings or quick con-
nects.

The A/C lines use special connectors called quick

connects. There are four quick connects in the sys-
tem. Two are located at the condenser and the other
two are located at the expansion valve. Each quick
connector has a clip installed on it.

All quick connects use two O-rings to seal the con-

nection. The O-rings are made from a special type of
rubber that is not affected by R-134a refrigerant.
O-ring replacement is required whenever lines are
removed and installed. Use only O-rings specified for
this vehicle. Failure to use the correct type of O-ring
will cause the connection to leak within a short
period of time.

OPERATION

CAUTION: Never attempt to remove a clip or dis-
connect a quick connect without reclaiming all
refrigerant from the air conditioning system. The
system must be empty.

When it is necessary to open the refrigeration sys-

tem, have everything needed to service the system
ready. The system should not be left open any longer
than necessary. Cap or plug all lines and fittings as

soon as they are opened. This will prevent the
entrance of dirt and moisture into the system. All
new lines and components should be capped or sealed
until they are ready to be used.

WARNING: AVOID BREATHING A/C REFRIGERANT
AND LUBRICANT VAPOR OR MIST. EXPOSURE MAY
IRRITATE EYES, NOSE AND THROAT. USE ONLY
APPROVED SERVICE EQUIPMENT MEETING SAE
REQUIREMENTS TO DISCHARGE R-134a SYSTEM.
IF ACCIDENTAL SYSTEM DISCHARGE OCCURS,
VENTILATE WORK AREA BEFORE RESUMING SER-
VICE.

R-134a SERVICE EQUIPMENT OR VEHICLE A/C

SYSTEM SHOULD NOT BE PRESSURE TESTED OR
LEAK TESTED WITH COMPRESSED AIR. SOME
MIXTURES OF AIR/R-134a HAVE BEEN SHOWN TO
BE COMBUSTIBLE AT ELEVATED PRESSURES.
THESE MIXTURES ARE POTENTIALLY DANGER-
OUS AND MAY RESULT IN FIRE OR EXPLOSION
CAUSING INJURY OR PROPERTY DAMAGE.

BLOWER MOTOR RESISTOR

DESCRIPTION

The blower motor resistor 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 Resistor in the Removal and
Installation section of this group for more informa-
tion.

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.

COMPRESSOR

DESCRIPTION

The TRS90 is a fixed displacement type compressor

(Fig. 1). This compressor uses an integral thermal

24 - 2

HEATING AND AIR CONDITIONING

limiter switch to protect it from overheating. The sys-
tem uses polyalkylene glycol synthetic wax-free
refrigerant oil SP-15 PAG.

CAUTION: Cleanliness

extremely

important.

Clean the surfaces around the suction and dis-
charge ports of the compressor before opening the
system. If compressor is removed from vehicle,
apply tape to the opened ports to prevent any con-
tamination.

OPERATION

The compressor is driven by the engine through an

electric clutch, drive pulley and belt arrangement.
The compressor is lubricated by refrigerant oil that is
circulated throughout the refrigerant system with the
refrigerant.

The compressor draws in low-pressure refrigerant

vapor from the evaporator through its suction port. It
then compresses the refrigerant into a high-pressure,
high-temperature refrigerant vapor, which is then
pumped to the condenser through the compressor dis-
charge port.

The compressor cannot be repaired. If faulty or

damaged, the entire compressor must be replaced.
The compressor clutch, pulley, clutch coil, and ther-
mal limiter switch are available for service.

COMPRESSOR CLUTCH, PULLEY, AND COIL

DESCRIPTION

The compressor clutch components provide a way

to drive the compressor. The compressor clutch
assembly consists of a stationary electromagnetic
coil, a hub bearing and pulley assembly, and a clutch
plate. The electromagnetic coil unit and the hub

bearing and pulley assembly are each retained on the
nose of the compressor front housing with snap rings.
The clutch plate is mounted on the compressor shaft
and secured with a nut. The compressor clutch and
coil assembly are the only serviced parts on the com-
pressor.

OPERATION

These components provide the means to engage

and disengage the compressor from the engine ser-
pentine accessory drive belt. When the clutch coil is
energized, it magnetically draws the clutch into con-
tact with the pulley and drives the compressor shaft.
When the coil is not energized, the pulley freewheels
on the clutch hub bearing, which is part of the pulley.
The compressor clutch and coil are the only serviced
parts on the compressor.

The compressor clutch is controlled by several com-

ponents: the heater-A/C mode control switch, the a/c
pressure transducer, the evaporator probe, the ther-
mal limiter switch, the compressor clutch relay, and
the Powertrain Control Module (PCM).

CONDENSER

DESCRIPTION

The condenser is a heat exchanger that allows the

high-pressure refrigerant gas being discharged by the
compressor to give up its heat to the air passing over
the condenser fins.

OPERATION

The condenser is located in the air flow in front of

the engine cooling radiator. When the refrigerant gas
gives up its heat, it condenses. When the refrigerant
leaves the condenser, it has become a high-pressure
liquid refrigerant. The volume of air flowing over the
condenser fins is critical to the proper cooling perfor-
mance of the air conditioning system. Therefore, it is
important that there are no objects placed in front of
the radiator grille openings in the front of the vehicle
or foreign material on the condenser fins that might
obstruct proper air flow. Also, any factory-installed
air seals or shrouds must be properly reinstalled fol-
lowing radiator or condenser service.

The condenser cannot be repaired and, if faulty or

damaged, it must be replaced.

ENGINE COOLING SYSTEM REQUIREMENTS

DESCRIPTION

To maintain ample temperature levels from the

heating-A/C system, the cooling system must be in
proper working order.

Fig. 1 TRS90 Compressor

HEATING AND AIR CONDITIONING

24 - 3

DESCRIPTION AND OPERATION (Continued)

OPERATION

The use of a bug screen is not recommended. Any

obstructions forward of the condenser can reduce the
effectiveness of the air conditioning system. Refer to
Group 0, Lubrication and Maintenance or Group 7,
Cooling System of this manual.

EVAPORATOR COIL

DESCRIPTION

The evaporator coil is located in the heater-A/C

housing, on the passenger side of the vehicle. The
evaporator coil is positioned in the heater-A/C hous-
ing so that all air that enters the housing must pass
over the fins of the evaporator before it is distributed
through the system ducts and outlets. However, air
passing over the evaporator coil fins will only be con-
ditioned when the compressor is engaged and circu-
lating refrigerant through the evaporator coil tubes.

The evaporator coil cannot be repaired and, if

faulty or damaged, it must be replaced.

OPERATION

Refrigerant enters the evaporator from the expan-

sion valve as a low-temperature, low-pressure mix-
ture of liquid and gas. As air flows over the fins of
the evaporator, the humidity in the air condenses on
the fins, and the heat from the air is absorbed by the
refrigerant. Heat absorption causes the refrigerant to
boil and vaporize. The refrigerant becomes a low-
pressure gas before it leaves the evaporator.

EVAPORATOR PROBE

DESCRIPTION

The evaporator probe is a 2 wire temperature sens-

ing element located at the coldest point on the face of
the evaporator. The switch is attached to the evapo-
rator coil with the sensing probe inserted into the
coil fins. The evaporator temperature probe prevents
condensate water on the evaporator coil from freez-
ing and obstructing A/C system air flow.

OPERATION

The probe is used to switch the clutch OFF before

evaporator freeze–up occurs. Output from the probe
is sampled by the Body Control Module. The clutch is
switched OFF when the probe temperature reaches
1.1°C (34°F). It is allowed to switch ON when the
probe temperature reaches 2.2°C (36°F).

EXPANSION VALVE

DESCRIPTION

The “H” valve-type thermal expansion valve (TXV)

is located at the front of the heater-A/C housing

between the liquid and suction lines and the evapo-
rator coil.

The expansion valve is a factory calibrated unit

and cannot be adjusted or repaired. If faulty or dam-
aged, the expansion valve must be replaced.

OPERATION

High-pressure, high temperature liquid refrigerant

from the liquid line passes through the expansion
valve orifice, converting it into a low-pressure, low-
temperature mixture of liquid and gas before it
enters the evaporator coil. A temperature sensor in
the expansion valve control head monitors the tem-
perature of the refrigerant leaving the evaporator coil
through the suction line, and adjusts the orifice size
at the liquid line to let the proper amount of refrig-
erant into the evaporator coil to meet the vehicle
cooling requirements. Controlling the refrigerant flow
through the evaporator ensures that none of the
refrigerant leaving the evaporator is still in a liquid
state, which could damage the compressor.

FILTER-DRIER

DESCRIPTION

The filter-drier is mounted on the right side of the

engine compartment in front of the heater-A/C hous-
ing. It is located in the liquid line between the con-
denser outlet and the evaporator inlet.

OPERATION

High-pressure liquid refrigerant from the con-

denser flows into the filter-drier. The filter-drier per-
forms a filtering action to prevent foreign material in
the refrigerant from contaminating the expansion
valve. A desiccant bag is mounted inside the filter-
drier canister to absorb any moisture which may
have entered and become trapped within the refrig-
erant system. In addition, during periods of high
demand air conditioner operation, the filter-drier acts
as a reservoir to store surplus refrigerant.

The filter-drier cannot be repaired. If the filter-

drier is faulty or damaged, if the refrigerant system
has been contaminated, or if the system has been left
open to the atmosphere for an indeterminable period,
it must be replaced.

HANDLING TUBING AND FITTINGS

DESCRIPTION

Kinks in the refrigerant tubing or sharp bends in

the refrigerant hose lines will greatly reduce the
capacity of the entire system.

24 - 4

HEATING AND AIR CONDITIONING

DESCRIPTION AND OPERATION (Continued)

Content .. 149 150 151 152 ..