air conditioning MITSUBISHI 3000GT 1991 Service Manual

55-1
HEATER, AIR
CONDITIONER
AND VENTILATION
CONTENTSM55AA- -
HEATERS AND AIR CONDITIONING................3HEATER UNIT*........................................................................22
SPECIFICATIONS
....................................................................3REFRIGERANT LINE................................................................35General Specifications
........................................................3RESISTOR................................................................................20Lubricants
............................................................................4SAFETY PRECAUTIONS........................................................9Sealant and Adhesive............................................................4
Service Specifications3SERVICE ADJUSTMENT PROCEDURES............................10........................................................
SPECIAL TOOLS4Charging Procedures............................................................11
i
........................................................................Charging the Refrigerant....................................................12Compressor Drive Belt Adjustment....................................11
HEATERS AND MANUAL AIR CONDITIONER5Compressor Noise................................................................16
................................................16
AIR CONDITIONER SWITCH................................................21Handling Tubing andFittings
Idle-up Operation Check....................................................17
BELT LOCK CONTROLLER20Performance Test................................................................15....................................................
BLOWER ASSEMBLYPower Relay Check............................................................17............................................................23Refrigerant Leak Repair Procedure....................................15COMPRESSOR........................................................................
27TestProcedures....................................................................10
CONDENSER AND CONDENSER FAN MOTOR................33TROUBLESHOOTING............................................................5
ENGINE COOLANT TEMPERATURE SWITCH....................
39VENTILATORS (AIR INLET AND AIR OUTLET)................38
EVAPORATOR
........................................................................
25VENTILATORS (INSTRUMENT PANEL)*............................36
HEATER CONTROL ASSEMBLY*
........................................18CONTINUED ON NEXT PAGE
SUPPLEMENTAL RESTRAINT SYSTEM (SRS)
(1)A Supplemental Restraint System (SRS), which uses a driver-side air bag, has been installed in the 3000GT.(2)The SRS includes the following components: impact sensors, SRS diagnosis unit: SRS warning light, air bagmodule, clock spring, interconnecting wiring. Other SRS-related components (that may have to be
removed/installed in connection with SRS service or maintenance) are indicated in the table of contents byan asterisk (*).
WARNING!(1)Improper service or maintenance of any component of the SRS, or any SRS-related component, can lead to
personal injury or death to service personnel (from inadvertent firing of the air bag) or to the driver (fromrendering the
SRS inoperative).(2) Service or maintenance of any SRS component or SRS-related component must be performed only at anauthorized MITSUBISHI dealer.
(3) MITSUBISHI dealer personnel must thoroughly review this manual, and especially its GROUP 52B
-Supplemental Restraint System (SRS), before beginning any service or maintenance of any component of theSRS or any SRS-related component.

HEATERS AND MANUAL AIR CONDITIONER - safety Pre=utm55-9
SAFETY PRECAUTIONSR-12 refrigerant is a chlorofluoro-carbon
(CFC) that
can contribute to the depletion of the ozone layer in
the upper atmosphere.
Ozone filters out harmful radiation from the sun.
To assist in protecting the ozone layer, Mitsubishi
Motor Sales of America recommends that a R-12
refrigerant recycling device that meets SAE stan-
dard
J1991 be used.
Contact an automotive service equipment supplier
for refrigerant recycling equipment that is available
in your area.
The refrigerant used in all air conditioner is R-l 2. It is
transparent and colorless in both the liquid and
vapor state. Since it has a boiling point of
-29.8”C(-21.7”F), at atmospheric pressure, it will be a vapor
at all normal temperatures and pressures. The vapor
is heavier than air, non-flammable, and nonexplo-
sive. It is nonpoisonous except when it is in direct
contact with open flame. It is noncorrosive except
when combined with water. The following precau-
tions must be observed when handling R-12.
CautionWear safety goggles when servicing the refri-
geration system.R-12 evaporates so rapidly at normal atmospheric
pressures and temperatures that it tends to freeze
anything it contacts. For this reason, extreme care
must be taken to prevent any liquid refrigerant from
contacting the skin and especially the eyes. Always
wear safety goggles when servicing the refrigera-
tion part of the air conditioning system. Keep a
bottle of sterile mineral oil handy when working on
the refrigeration system. Should any liquid re-
frigerant get into the eyes, use a few drops of
mineral oil to wash them out. R-12 is rapidly
absorbed by the oil. Next splash the eyes with
plenty of cold water. Call your doctor immediately
even though irritation has ceased after treatment.
CautionDo not heat R-12 above 52°C
(125.6”F).
M55PAAFIn most instances, moderate heat is required to
bring the pressure of the refrigerant in its container
above the pressure of the system when charging or
adding refrigerant. A bucket or large pan of hot
water not over 52°C
(125.6”F) is all the heat required
for this purpose. Do not heat the refrigerant contain-
er with a blow torch or any other means that would
raise temperature and pressure above this tempera-
ture. Do not weld or steam clean on or near the
system components or refrigerant lines.
Caution
Keep R-12 containers upright when charging the
system.When metering R-12 into the refrigeration system,
keep the supply tank or cans in an upright position. If
the refrigerant container is on its side or upside
down, liquid refrigerant will enter the system and
damage the compressor.
CautionAlways work in a well-ventilated room.
Good ventilation is vital in the working area.
Although R-12 vapor is normally nonpoisonous,
contact with an open flame can cause the vapor to
become very poisonous. A poisonous gas is pro-
duced when using the flame-type leak detector.
Avoid inhaling the fumes from the leak detector.
CautionDo not allow liquid refrigerant to touch bright
metal.Refrigerant will tarnish bright metal and chrome
surfaces, and in combination with moisture can
severely corrode all metal surfaces.
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CautionRefrigerantR-l 2iAdaptorNever use the high pressure side as this may cause
/valve
refrigerant to flow back, using rupture of the servicecan.(7) Start the engine. Charge valvergmg hose
55-14 HEATERS AND MANUAL AIR CONDITIONER - Service Adjustment procedures
CORRECTING LOW REFRIGERANT LEVEL
(I) Install the charge valve to the service can with its handle
turned back all the way.
(2) Connect the charging hose to the charge valve.
(3) Connect the adaptor valve to the charging hose with itsL&lhandle turned back all the way.
(4) Tighten the charge valve handle to puncture the can.
(5) Operate the adaptor valve handle to bleed air.
(6) Install the adaptor valve to the low pressure side service
valve.
(8) Operate the air conditioner and set at the lowest tempera-
ture (MAX. COOL).
(9) Fix the engine speed at 1,500 rpm.
(10)Open the adaptor valve and charge refrigerant checking
level with the sight glass.
(1 l)Upon completion of charging, close the adaptor valve and
20M0128charge valve.
(12)Remove the adaptor valve from the service valve.
NOTEIf the service can is not emptied completely, keep the
charge valve and adaptor valve connected to the can for
next charging.
Adaptor
valve
\
DISCHARGING SYSTEMUse the refrigerant recovery unit to discharge refrigerant gas
from the system.
NOTERefer to that Refrigerant Recovery and Recycling Unit Instruc-
tion Manual for operation of the unit.
REFILLING OF OIL IN THE AIR CONDITIONER SYSTEM
Too little oil will provide inadequate compressor lubrication and
cause a compressor failure. Too much oil will ,increase
discharge air temperature.
When a
FX-105VS compressor is installed at the factory, it
contains
160 cc (9.8 cu.in.) of refrigerant oil. While the air
conditioning system is in operation, the oil is carried through
the entire system by the refrigerant.
Some of this oil will be trapped and retained in various parts of
the system.
When the following system components are charged, it is
necessary to add oil to the system to replace the oil being
removed with the component.
Condenser: 8 cc
(5 cu.in.)Evaporator: 72 cc (4.4
cu.in.)Piping: 9.6 cc
(6 cu.in.)Receiver drier: 6.4 cc
(.4 cu.in.)
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HEATERS AND MANUAL AIR CONDITIONER -Service Adjustment Procedures 55 15
PERFORMANCE TESTM55FWAH
(I) Park the tested vehicle at the area which is not exposed to
the direct sunlight.
(2) Connect a tachometer.
(3) Turn back the adaptor valve handle all the way and install
the adaptor valves to the high pressure and low pressure
service valves.
(4) Connect the gauge manifold to the adaptor valves.
(5) Tighten the adaptor valve handle and open the service
valves.
(6) Start the engine.
(7) Set the controls to the air conditioner as follows:
Air conditioning switch: Air conditioner
- ON position
Mode selection: Face position
Temperature control: MAX. COOL position
Air selection: Recirculation position
Blower switch: HI (Fast) position
(8) Adjust engine speed to 1,000 rpm with air conditioner
clutch engaged.
(9) Engine should be warmed up with doors, windows close,
and hood open.
(1O)lnsert a thermometer in the center air conditioner outlet and
operate the engine for 20 minutes.
(II )Note the discharge air temperature.
NOTEIf the clutch cycles, take the reading before the clutch
disengages.
Performance Temperature ChartGarage
amb;in,L;am-perature21 (70)
26.7 (80)32.2 (90)37.8 (100)43.3 (110)
Iperature Dischargeair "C tem- ("F)(32.0 0.0- -3.0 37.4)(33.8 1.0- -4.0 39.2)(33.8 1.0- -4.0 39.2)(33.8 1.0- -4.0 39.2)(35.6 2.0- -41.0) 5.0
ICompressor pressure kPa discharge (psi)(98.1 690- -105.3) 740(110.9 780- -830 118.1)(123.7 870- -920 130.9)(153.6 1,080- -1,130 160.7)(172.1 1,210- -1,260 179.2)Compressor suction130
-190130-190130-190130-190130-190
pressure kPa (psi)(18.5-27.5)(18.5-27.5)(18.5-27.5)(18.5-27.5)(18.5-27.5)
REFRIGERANT LEAK REPAIR PROCEDUREM55FHAQ
LOST CHARGEIf the system has lost all charge due to a leak:
(1) Evacuate the system. (See procedure.)
(2) Charge the system with approximately one pound of
refrigerant.
(3) Check for leaks.
(4) Discharge the system.
(5) Repair leaks.
(6) Replace receiver drier.
Caution
Replacement filter-drier units must be sealed while instorage. The drier used in these units will saturate
water quickly upon exposure to the atmosphere. When
installing a drier, have all tools and supplies ready forquick reassembly to avoid keeping the system open
any longer than necessary.(7) Evacuate and charge the system.
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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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