1991 MITSUBISHI ECLIPSE belt

HEATERS AND AIR CONDITIONING - Service Adjustment Procedures 249*I3
--Air-therm0
sensor
Air inlet
sensor
E>aporator(3)
Set the gauge manifold in place and check whether or not
the pressure at the high-pressure side has become the
dual-pressure switch activation pressure.
(4) Replace the switch if, under ordinary conditions, there is no
continuity.Caution
The condition can be considered to be satisfactory if
there is continuity.
Never increase the pressure in a deliberate attempt to
obtain an abnormally high temperature, because to do
so risks blowing the compressor relief valve.AIR-THERM0 SENSOR AND AIR-INLET SENSOR
If frost forms on the surfaces of the evaporator fins, the cause
might be a malfunction of
air-therm0 sensor.
The temperature of the air-flowing from the evaporator’s outlet
is sensed by the thermistor, and the signals conveying this dataare input to the air conditioner control unit, thus switching the
compressor’s clutch ON or OFF.
This functions when the evaporator’s air-flow is low, or the
evaporator’s fins are clogged by dust, etc., or when the amountof refrigerant is insufficient.
These sensors detect the temperature within the passenger
compartment and the temperature at the cooling unit inlet,
thus causing changes of the resistance value, and this data is
provided to the air conditioner control unit as input.
How to Test the Therm0 Sensor and Air-Inlet Sensor
(1) Disconnect the sensor’s connector at the evaporator case,
and by using an ohmmeter, measure the resistance. The
resistance is normal if it is within the range shown in the
figure at the left; if the resistance is not normal, replace.
(2) If the sensor is normal, there is a malfunction of the air
conditioner control unit, and it should be replaced.
Standard value:
Passenger compartment temperature sensor resist-
ance value:
0°C (32°F)4,852+243 (S-2)
15°C (59°F)2,341+234 (S-2)
25°C (77°F)1,500+150 (52)
ENGINE COOLANT TEMPERATURE SWITCH
<2.0L DOHC Engine>
The engine coolant temperature switch is connected in series
with the compressor magnetic clutch power relay.
It disengages the compressor when the temperature of
engine coolant rises above
115°C (239°F).This is designed to prevent engine overheating when cooling
air is not sufficient for the condenser and radiator. If the enginecoolant temperature switch operates to disengage the com-
pressor, check for the condenser and radiator surface condi-
tions, belt tension and engine coolant level and correct, if
necessary.

HEATERS AND AIR CONDITIONING - Service Adiustment Procedures 24-23
<
we2ouo2er
< 1.8L Engine>Tension/ wllevO-RING INSTALLATION
(1) Clean sealing surface.
(2) Make sure O-ring does not have any scratches.
(3) Connect fitting, install fastener, and torque to amount
shown in the illustration.
The internal parts of the refrigeration system will remain in
a state of chemical stability as long as pure-moisture-free
R-12 and refrigerant oil is used. Abnormal amounts of dirt,
moisture of air can upset the chemical stability and cause
operational troubles or even serious damage if present in
more than minute quantities.
When it is necessary to open the refrigeration system, have
everything you will need to service the system ready so the
system will not be left open any longer than necessary. Capor plug all lines and fittings as soon as they are opened to
prevent the entrance of dirt and moisture. All lines and
components in parts stock should be capped or sealed until
they are ready to be used. All tools, including the refrigerant
dispensing manifold, the gauge set manifold and test hosesshould be kept clean and dry.
COMPRESSOR DRIVE BELT ADJUSTMENT N24FJAESatisfactory performance of the air conditioning system is
dependent upon drive belt condition and tension. If the proper
tensions are not maintained, belt slippage will greatly reduce airconditioning performance and drive belt life. To avoid such
adverse effects, the following service procedure should be
followed:
(1) Measure the deflection with a force of
IOON (22 Ibs.)applied to belt mid-point between tension pulley and
compressor pulley.
(2) Any belt that has operated for a minimum of one half-hour
is considered to be a “used” belt. Adjust air conditioning
drive belt at the time of new-car preparation.
(3) Check drive belt tension at regular service intervals and
adjust as needed.
Standard value:
When a new belt is installed<1.8L Engine>4-5 mm
(.16-.2 in.)
<2.0L DOHC Engine> 4.5-5 mm (.18-.2 in.)
When the used belt’s tension is adjusted
5.5-6 mm
(.22-.24 in.)

24-24 HEATERS AND AIR CONDITIONING - Service Adjustment Procedures
COMPRESSOR NOISENUFIABWhen investigating an air conditioning related noise, you must
first know the conditions when the noise occurs. These
conditions are: weather, vehicle speed, in gear or neutral,
engine temperature or any other special conditions.
Noises that develop during air conditioning operation can oftenbe misleading. For example: what sounds like a failed front
bearing or connecting rod, may be caused by loose bolts, nuts,mounting brackets, or a loose clutch assembly. Verify acces-
sory drive belt tension (power steering, or alternator).
Improper accessory drive belt tension can cause a misleading
noise when the compressor is engaged and little or no noise
when the compressor is disengaged.
Drive belts are speed sensitive. That is, at different engine
speeds, and depending upon belt tension, belts can develop
unusual noises that are often mistaken for mechanical prob-
lems within the compressor.
Adjustment Procedures
(1) Select a quiet area for testing. Duplicate conditions as
much as possible. Switch compressor on and off several
times to clearly identify compressor noise.
To duplicate high ambient conditions (high head pressure),restrict air flow through condenser. Install manifold gauge
set to make sure discharge pressure doesn’t exceed 2,070
kPa (300 psi).
(2) Tighten all compressor mounting bolts, clutch mounting
bolt, and compressor drive belt. Check to assure clutch coilis tight (no rotation or wobble).
(3) Check refrigerant hoses for rubbing or interference that cancause unusual noises.
(4) Check refrigerant charge (See “Charging the System”).
(5) Recheck compressor noise as in Step 1.
(6) If noise still exists, loosen compressor mounting bolts and
retorque. Repeat Step 1.
(7) If noise continues, replace compressor and repeat Step 1.
Condenser fan motor relay,
Magnet clutch
relay, Blower
motor High
relayHeater relayML0312
16W908
POWER RELAY CHECKNUFNAE
NOTEFor information concerning the installation position of each
relay, refer to
P.24-8.CONDENSER FAN MOTOR RELAY, MAGNET CLUTCH
RELAY, BLOWER MOTOR HIGH RELAY, HEATER RELAY
Check for continuity between the terminals when- the battery
power-supply is applied to terminal (2). and terminal (4) is
grounded.
1 When current flows 1 Between terminals l-3 1 Continuity1
I
When no currentBetween terminals l-3 No continuity
flowsBetween terminals 2-4 Continuity
IKinks in the refrigerant tubing or sharp bends in the
Never attempt to rebend formed lines to fit. Use the
refrigerant hose lines will greatly reduce the
capac-correct line for the installation you are servicing.
ity of the entire system. High pressures are
pro-A good rule for the flexible hose lines is keep the
duced in the system when it is operating. Extreme
radius of all bends at least 10 times the diameter of
care must be exercised to make sure that all
the hose.
connections are pressure tight. Dirt and moisture
Sharper bends will reduce the flow of refrigerant.
can enter the system when it is opened for repair or
The flexible hose lines should be routed so that theyreplacement of lines or components. The following
are at least 80 mm (3 in.) from the exhaust manifold.precautions must be observed.
It is good practice to inspect all flexible hose lines atThe system must be completely discharged before
least once a year to make sure they are in good
opening any fitting of connection in the refrigeration
condition and properly routed.
Fsystem. Open fittings with caution even after the
Unified plumbing connections with O-rings. These
4’system has been discharged. If any pressure is
noticed as a fitting is loosened, allow trappedO-rings are not reusable.
pressure to bleed off very slowly.

HEATERS AND AIR CONDITIONING - ComDressor24-37
COMPRESSOR <7.8L Engine>
em REMOVAL AND INSTALLATION
F)
*Removal of the distributor CapPost-installation Operation
@Charging of Refrigerant
(Refer to P.24-21.)@Adjustment of Compressor DriveBelt (Refer to P.24-23.)*Checking for Gas Leakage(Refer to P.24-15.)*Performance Test(Refer to P.24-16.)Removal steps of compressor drive belt and
tension pulley
l *1, Compressor drive belt2. Tension pulley assembly installation bolt
3. Tension pulley assembly4. Bolt
5. Tension pulley6. Bolt
7. Adjustment plate
8. Tension pulley bracket2
13-15
ft.lbs.45-55 Nm
H 12 11
-10
2OAO456Removal steps of compressor
4*1. Compressor drive belt
9. Magnetic clutch harness connector
+e l * 10. Suction hose connection+e I)+ 11. Discharge hose connectionl a 12. O-rings
+* l + 13. Compressor14. Compressor bracket
NOTE(1) Reverse the removal procedures to reinstall.(2) l * : Refer to “Service Points of Removal”.
(3) W : Refer to “Service Points of Installation”.(4) m : Non-reusable parts.

24-38HEATERS AND AIR CONDITIONING - Compressor
2OAOO87
SERVICE POINTS OF REMOVALN248BACa1. REMOVAL OF COMPRESSOR DRIVE BELT
A;i(1) Loosen “A” for holding the tension pulley.
(2) Loosen bolt “B” for adjustment, and remove the
4compressor drive belt.
10. DISCONNECTION OF SUCTION
HOSE/ 11. DIS-
CHARGE HOSE
If the hoses are disconnected, cap the hoses with a blank
plug to prevent entry of dust, dirt, and water.
13. REMOVAL OF COMPRESSOR
Caution
Lay the towel on the brake tube to protect them. When
install the compressor, do not damage the brake tubes.This work must be done carefully so as not to spill the
compressor oil.
INSPECTIONN248CACl Checking for heat damage of the tension pulley.
lCheck for excessive play or deflection of the tension pulley.l Check for unusual wear of the tension pulley.
l Check for hardening of the compressor drive belt.
/J+-
lCheck for unusual wear or abrasion of the compressor drive&’
belt.
CONTINUITY CHECK OF THE COMPRESSOR’S MAGNETIC
CLUTCH
(1) Disconnect the compressor’s connector.
(2) Check to be sure that there is continuity between body
ground and terminal
@ at the compressor side.

24-40HEATERS AND AIR CONDITIONING - CompressorCOMPRESSOR
<2.0L DOHC Engine>
REMOVAL AND INSTALLATIONPre-removal OperationaDischarge of Refrigerant
(Refer to
P.24-19.)l Removal of VSV Bracket on theCowl Top <2.0L Turbo>
*Disconnection of High-tension
Cables and Connections for Igni-
tion Coil etc.
*Removal
of Center Bearing
Bracket Mounting Bolt
(Referto GROUP 2-Drive Shaft.)Post-installation Operation
*Installation of VSV Bracket<2.0L Turbo>
*Installation of Center
Bearin!Bracket Mounting Bolt *Adjustment of Compressor Drivt
Belt (Refer to P.24-23.)Kharging of Refrigerant
(Refer to P.24-21.)l ehecking for Gas ‘Leakage(Refer to P.24-15.)l Performance Test(Refer to P.24-16.)
N24SA.-tension pulley
1. Alternator drive belt
4*2. Tension pulley assembly installation boltI)+ 3. Tension pulley assembly~~ 2: Grpressor dnve belt
6. Tension pulley
7. Bolt
8. Adjustment plate
9. Tension pulley bracket23-34
ft.lbs.45-55 Nm
33-39 ft.lbs.
2OAO4.58Removal steps of compressor drive belt andRemoval steps of compressor
1. Alternator drive belt
l *2. Tension pulley assembly installation boltl +3. Tension pulley assemblyl +4. Compressor drive belt10. Magnetic clutch harness connector+* l * 11. Suction hose connectionl + 12. Discharge hose connectionl + 13. O-rings
** l * 14. Compressor15. Compressor bracket
NOTE(I) Reverse the removal procedures to reinstall.(2) +e : Refer to “Service Points of Removal”.
(3) l + : Refer to “Service Points of Installation”.(4) m : Non-reusable parts.

HEATERS AND AIR CONDITIONING - Compressor24-41
2OPOO12
Air condltlonercompressor
SERVICE POINTS OF REMOVALNusenD2. REMOVAL OF TENSION PULLEY ASSEMBLY.,
lN-
STALLATION BOLTS
(1) After loosening nut A (for holding the tension pulley),
loosen bolt B (for adjustment) and reduce the tension ofthe compressor drive belt to zero.
(2) Remove the tension pulley assembly installation
bolts:and then remove the tension pulley assembly together
with the compressor drive belt.
11. DISCONNECTION OF SUCTION
HOSE / 12. DIS-CHARGE HOSE
Refer to
P.24-38.14. REMOVAL OF COMPRESSOR
Refer to
P.24-38.
INSPECTIONN24SCADRefer to
P.24-38.CONTINUITY AND OPERATION CHECK OF THE COM-
PRESSOR’S MAGNETIC CLUTCH
Refer to
P.24-38.
SERVICE POINTS 03: INSTALLATIONN24SDAEa14. INSTALLATION OF COMPRESSOR
Refer to
P.24-39.13. CONNECTION OF
0-RING/lS. DISCHARGE HOSE/
11. SUCTION HOSE
Refer to
P.24-39.4. INSTALLATION OF COMPRESSOR DRIVE
BELT/3.TENSION PULLEY ASSEMBLY
Attach the compressor drive belt to the crankshaft pulley
and the compressor’s pulley, and then install the tension
pulley assembly.
NOTE(1) Hold the tension pulley assembly so that the compres-
sor drive belt does not slip out of place; and while doingso install the tension pulley assembly.
(2) Install the tension pulley assembly installation bolts in
the
@ + @ sequence.

24-50HEATERS AND AIR CONDITIONING -Ventilators (Air Inlet and Air Outlet)
VENTILATORS (AIR INLET AND AIR OUTLET)
‘- ’
REMOVAL AND INSTALLATION
Inlet garnish removal steps
l +1. Windshield wiper arms
2. Front deck garnish3.
Inlet garnish (right)
4. Inlet garnish (left)
Rear ventilation removal steps
l *5. Quarter trim
6. Automatic seat belt motor fastening bolts
and screws
l *
7. Side protect moulding quarter
8. Rear ventilation duct
!PTkeverse the removal procedures to reinstall.(2) +* : Refer to “Service Point of Removal:.(3) l * : Refer to “Service Points of Installation”
SERVICE POINTS OF REMOVAL5. REMOVAL OF QUARTER TRIM
’Refer to GROUP
23-Trims.
N24YEAC6. REMOVAL OF AUTOMATIC SEAT BELT MOTOR
FASTENING BOLTS AND SCREWS
Remove the bolts and screws which fasten the automatic
seat belt motor, and slide the motor for working.
8. REMOVAL OF REAR
VENTllATlON DUCT
For removal and installation, pass the rear ventilator duct
through the opening of the automatic seat belt motor as
illustrated.
SERVICE POINTS OF INSTALLATION1. INSTALLATION OF WINDSHIELD WIPER ARMS
Refer to GROUP
8-Windshield wipers.