belt MITSUBISHI 3000GT 1991 Repair Manual

55-2FULL AUTO AIR CONDITIONER........................40OTHER PARTS........................................................................62
AIR-CONDITIONER CONTROL PANEL*,POWER TRANSISTOR, BELT LOCK CONTROLLER........57
AIR-CONDITIONER CONTROL UNIT*................................56
REFRIGERANT LINE................................................................62
COMPRESSOR
........................................................................62SAFETY PRECAUTlONS........................................................56
CONDENSER AND CONDENSER FAN MOTOR
................
62SENSORS....................................................................................60
DAMPER CONTROL MOTOR ASSEMBLY*........................
58SERVICE ADJUSTMENT PROCEDURES............................56
ENGINE COOLANT TEMPERATURE SWITCH
....................62
TROUBLESHOOTING............................................................40

HEATER, AIR CONDITIONER AND VENTILATION - Specifications55-3
HEATER, AIR CONDITIONER AND VENTILATION
LSPECIFICATIONSM55CA. -
/’
L;
GENERAL SPECIFICATIONS
Items
Heater unit
Type
Heater control assembly
Compressor
Model
Refrigerant unit lubricant
cc (cu.in.1
V belt sizemm (in.)
Dual pressure switch
High pressure switch
kPa (psi)
Low pressure switchkPa (psi)
Freezer prevention
“C (“F)
Refrigerant and quantityg (oz.)
Specifications
Three-way-flow full-air-mix system
Dial type
Scroll type (FX-105 VS)
FREOL S-83 or SUNISO 5GS160 & 20 (9.8 + 1.2)
1,150 (45.3)
OFF: 2,700 (384)ON: 2,100 (299)
OFF: 210 (30)
ON
: 235 (33)
Air temperature thermostatOFF: - 2 (28.4)
ON: 2 (35.6)
R-l 2Approx. 970 (34)
SERVICE SPECIFICATIONSM55CB. -
Items
Standard value
Idle speed when air conditioner onrpm
Resister resistance value1R
Refrigerant temperature sensor
Sensor-ON temperature
“C (“F)
Sensor-OFF temperature“C (“F)
Revolution pick up sensor standard resistance 0
Clutch clearancemm (in.)
Engine coolant temperature switch
Switch-OFF temperature
“C (“F)

Air mix damper potentiometer motor assembly resistanceMAX. HOT
kQMAX. COOL
kS1
Outlet selector damper potentiometer assembly resistanceDEF. position
kS1FACE position
kfl
Water temperature sensor
Sensor-ON temperature
“C (“F)
Specifications
900
f 100 CA/T at P range>
1.76
- 2.06 (Across terminals @and 0)
1 .I 0 - 1.26 (Across terminals @and 0)
0.38 - 0.44 (Across terminals @and @)
Approx. 110 (230) or less
Approx. 155 (311) or more
405
f 35 when ambient temperature is 20°C (68°F)
0.4 - 0.6 (.Ol - .02)
112-118(233-244)
0.2
4.9
2.0
4.3
26.5 f 4 (79.7 + 7)
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HEATERS AND MANUAL AIR CONDITIONER -Service Adjustment Procedures 55 1 1
lr In et sensor
2oFoo57
UC03xD:c.-;am$2lYXSC0x.x
xa0:: :,:::25 cc,ii 77h>Temperature20A043F
argqse
20M012FIN-THERM0 SENSOR AND AIR-INLET SENSOR
(1) Disconnect the sensor’s connector at the evaporator case,
and by using an ohmmeter, measure the resistance.
If the resistance is within
+I 0% of value of the characteris-
tic curve, the sensor is functioning normally.
(2) If the sensor is normal, there is a malfunction of the air
conditioner control unit, and it should be replaced.
COMPRESSOR DRIVE BELT ADJUSTMENTM55FJAGRefer to GROUP 11
- Engine Adjustment.
CHARGING PROCEDURESM55FTAB
INSTALLATION OF CHARGE EQUIPMENT
(I) Turn back the adaptor valve handle all the way and install
each adaptor valve to the high and low pressure service
valves.
(2) Tighten the adaptor valve handle and open the service
valves.
(3) Connect the charge valve to the T-joint:
(4) With the charge valve handle turned back all the way, install
the service can.
(5) Connect each charge equipment as illustrated.
NOTE
(4) Do not connect the high and low pressure sides
adversely. (Connect high pressure side to the con-
denser and low pressure side to the evaporator.)
(2) The indications
“DIS” and “SUC” on the compressor
indicate high and low pressure sides respectively.
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55-16 HEATERS AND MANUAL AIR CONDITIONER -Service Adjustment Procedures
LOW CHARGE~
If the system has not lost all of its refrigerant charge; locate and
repair all leaks. If it is necessary to increase the system
pressure to find the leak (because of an especially low charge)
‘iaadd of refrigerant. If it is oossible to reoair the leak without
discharging-the refrigerant system, use the procedure for
correcting low refrigerant level.
HANDLING TUBING AND FITTINGSM55FlAFKinks in the refrigerant tubing or sharp bends in the refrigerant
hose lines will greatly reduce the capacity of the entire system.
High pressures are produced in the system when it is
operating. Extreme care must be exercised to make sure that
all connections are pressure tight. Dirt and moisture can enter
the system when it is opened for repair or replacement of lines
or components. The following precautions must be observed.
The system must be completely discharged before opening
any fitting of connection in the refrigeration system. Open
fittings with caution even after the system has been dis-
charged. If any pressure is noticed as a fitting is loosened, allow
trapped pressure to bleed off very slowly.
Never attempt to rebend formed lines to fit. Use the correct
line for the installation you are servicing.
A good rule for the flexible hose lines is keep the radius of all
bends at least 10 times the diameter of the hose.
Sharper bends will reduce the flow of refrigerant. The flexible
hose lines should be routed so that they are at least 80 mm (3
in.) from the exhaust manifold. It is good practice to inspect all
flexible hose lines at least once a year to make sure they are in
good condition and properly routed.
\ Aj iUnified plumbing connections with O-rings. These O-rings are
-not reusable.
I
COMPRESSOR NOISEM55FlAD
When investigating an air conditioning related noise, you must
first know the conditions when the noise occurs. These
conditions are: weather, vehicle speed, in gear on neutral,
engine temperature or any other special conditions.
Noises that develop during air conditioning operation can often
be 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.
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HEATERS AND MANUAL AIR CbNDlTlONER -Service Adjustment Procedures 55 17
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 coil
is tight (no rotation or wobble).
(3) Check refrigerant hoses for rubbing or interference that can
cause unusual noises.
(4) Check refrigerant charge. (See “Charging 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.
POWER RELAY CHECKMBBFNAK(1) Remove the radiator fan motor relays (HI) and (LO) from the
relay box on the right of the engine compartment.
(2) Remove the radiator fan motor relay (air conditioner),
condenser fan motor relays (HI) and (LO), and
air-conditioner compressor relay from the relay box on the left
of the engine compartment.
(3) Remove the blower motor relay from the junction box.
(4) Remove the blower motor HI relay from the blower case
assembly.
(5) Check the continuity between terminals using a circuit
tester.
J Blower m.otor HI relay\2OFOO6l
IDLE-UP OPERATION CHECKM55FOAB
(1) Before inspection and adjustment set vehicle in the
following condition:
lEngine coolant temperature: 80 - 95°C (176 - 203°F)
lLights, electric cooling fan and accessories: Set to OFF
l Transaxle: Neutral (N or P for vehicles with
A/T)l Steering wheel: Straightforward
(2) Check to be sure that the idling speed becomes the
standard value when the air conditioner switch is switched
ON and the air conditioner is activated.
Standard value: 900
+ 100 rpm
NOTEThere is no necessity to make an adjustment, because the
idling speed is automatically adjusted by the ISC” system.
If, however, there occurs a deviation from the standard
value for some reason, check the ISC” system.
ISC: Idle Speed Control
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55-20 HEATERS AND MANUAL AIR CONDlTlONER - Resistor, Belt Lock Controller
RESISTOR, BELT LOCK CONTROLLERM55JA- -
REMOVAL AND INSTALLATION
viRemoval steps
1. Stoooer
2OFOO732. Globk box outer case assembly
3. Resistor
4. Under cover
5. Belt lock controller
- 2OPOOl
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INSPECTION
RESISTOR CHECK
hl55JCADUsing a circuit tester, measure the resistance between the
terminals indicated below.
The condition can be considered satisfactory if the value
measured at this time is equivalent to the standard value.
Standard value
Terminals measuredStandard value fi
Between terminals a-- @Approx. 1.79 - 2.06
Between terminals
@ -@Approx. 1 .I 0 - 1.26
Between terminals @ - @Approx. 0.38 - 0.44vision

HEATERS AND MANUAL AIR CONDITIONER - Compressor55-27
COMPRESSOR
M55SA- -
/REMOVAL AND INSTALLATION
iJ
iPre-removal Operation
l Discharge of the Refrigerant(Refer to P.55-14.)9.0 Nm
7.Oft.lbs.
\Post-installation Operation
l Adjustment of the Compressor
Drive Belt (Refer to GROUP 11 -Service Adjustment Procedures.)l Charging of Refrigerant(Refer to P.55-11.)21 Nm
15 ftlbs.Removal steps
a*1. Compressor drive belt
2. Condenser fan motor assembly
4*3. Connection of suction hose and discharge
41) l +4. !%znator (Refer to GROUP l6-Alternator.)*I) l * 5. Compressor
6. Idler pulley
7. Compressor bracket
!I zorr-rion pulley assembly;
;: Fontsion pulley
12. Adjustment plate
13. Tension pulley bracket6
45 Nm
33 ft.lbs.
52ONOO89Compressor oil:
Freol S-83 or Suniso 5GS
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55-28HEATERS AND MANUAL AIR CONDITIONER - Comtxessor
20F0067
SERVICE POINTS OF REMOVALM55SBAE1. REMOVAL OF COMPRESSOR DRIVE BELT
(1) Loosen bolt “A” for holding the tension pulley.
(2) Loosen bolt “B” for adjustment, and remove the
‘J
compressor drive belt.
3.REMOVAL OF SUCTION HOSE AND DISCHARGE HOSE
If the hoses are disconnected, cap the hoses with a blankplug to prevent entry of dust, dirt, and water.
5. 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.
INSPECTIONM55SCAEl Checking for heat damage of the tension pulley.
l
Check for excessive play or deflection of the tension pulley.l Check for unusual wear of the tension pulley.
l Check for hardening of the air conditioner belt.
lCheck for unusual wear or abrasion of the air conditioner ,
belt.
\d’
OPERATION CHECK OF THE COMPRESSOR’S MAGNETIC
CLUTCH
(1) Connect terminal @ at the compressor side to the positive
(+) terminal of the battery, and ground the negative (-)terminal of the battery to the compressor.
(2) The condition of the compressor’s magnetic clutch can beconsidered satisfactory if the operation sound (a “click”
sound) of the magnetic clutch can be heard when this
check is made.
SERVICE POINTS OF INSTALLATIONM55SDAF5. INSTALLATION OF COMPRESSOR
If a new compressor is installed, first adjust the amount of
oil according to the procedures described below, and then
install the compressor.(1) Measure the amount (X cc) of oil within the removed
compressor.
(2) Wipe away (from the new compressor) the amount ofoil calculated according to the following formula, and
then install the new compressor.
New compressor oil amount
160 cc (9.8 cu.in.) - X cc= Y cc
NOTE
Y cc indicates the amount of oil in the refrigerant line,l/jthe condenser, the cooling unit, etc.
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55-36 HEATERS AND MANUAL AIR CONDITIONER -Ventilators (Instrument Panel)
VENTILATORS (INSTRUMENT PANEL)M55YA- -
REMOVAL AND INSTALLATION
-16
/‘4
Removal steps
l * +a1. Knee protector
(Refer to GROUP 52A-Instrument Panel.)
2. Foot shower duct
3. Lap cooler duct
4. Under cover
5. Belt lock controller
6. Side defroster hoses A
7. Duct (Vehicles without air conditioner)
** l +8. instrument panel (Refer to GROUP 52A-instrument Panel.)
9. Center duct
10. Air duct (right side)
11. Air duct (left side)12. Distribution duct (center)
13.Defroster duct14. Side defroster hoses B
15. Defroster garnishes
16.Photo sensor17. Center air outlet assembly
18. Side air outlet assembly
19. Distribution duct (foot)2OFOO55
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FULL AUTO AIR CONDITIONER - Troubleshooting55-495. Inspection of belt lock controller circuit
Compressor relay
tAir conditioner control unitAir conditioner
+control panelAir
condltloner,c.compressor commandAH condmonerarithmetic
circuitcompressor ONstgnal
ComparatorAir condltlonercompressor ON signal20 FOO58
Revolution pickup sensor
LiTroubleshooting Hintsl Air conditioner control unit terminal voltages
Terminal No.
Signal nameConditionTerminal voltage
11Air conditioner outputCompressor ONIO V to battery voltage
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