1987 MITSUBISHI MONTERO Charging

METERS AND GAUGES - Indicators and Warning Lights 8-141
INDICATORS AND WARNING
LIGHTS
Symbol
Operation
Turn signal indicator
+e3 This indicator flashes, as do the same side of turn-signal light
flashes. If the turn-signal light is burnt out, the blinking of
indicator slows down.
This indicator is common with hazard light.
0
High beam indicator
- This indicator illuminates when the headlights are on high
= beam.
=
* Door-ajar warning light
This warning light comes on when the door is either open or
not completely closed.
4 Fasten seat belt indicator
This indicator goes on for four to eight seconds when the
ignition key is in “ON” position, even if the driver has fastened
his seat belt.
BRAKE
Brake warning light
This warning light comes on when the ignition key is in “ON”
position, and goes off after the engine has started. This
warning light comes on when the parking brake is applied
or brake fluid level falls less than the specific level.
III Charging warning light This warning light comes on when the ignition key is in
- + “ON” position, and goes off after the engine has started.
This warning light comes on when the drive belt breaks
or the trouble occurs in the charging system.
Oil pressure warning light This warning light comes on when the ignition key is in “ON”
P position, and goes off after the engine has started. This
warning light comes on when the oil fails or the trouble
occurs in the oil circulating system.
00
Overdrive indicator
This indicator will illuminates when the overdrive control
OFF
switch is switched to the “OFF” position.
68R0133
A/T
A/T oil temperature warning light This A/T oil temperature warning light comes on when
TEMP automatic transmission fluid temperature becomes abnor-
mally high.
68WO68
Free-wheeling hub indicator
YEL This indicator comes on when the automatic free-wheeling
hubs are locked.
68WO80
z4 4WD indicator This indicator will light up when the transfer case shift lever is
shifted to the four wheel driving position (either the “4H” or the
“4L” position) and the ignition key is in the “ON” position.
CHECK
EGR
EGR warning light The EGR warning light will illuminate every 50,000 miles of
driving. When this occurs, bring the vehicle to an authorized
dealter to have the EGR system checked.
) STB Revision

AIR-CONDITIONING-Service Adjustment Procedures
SERVICE ADJUSTMENT PROCQDURES 24-29 N24FDAD
MANIFOLD GAUGE SET INSTALLATUON Discharge
W gauge
Suction
gauge
Suction
gauge
valve Manifold Gauge Valves should be closed
when connecting the manifold gauge set to the service port of the
compressor and the discharge hose. The suction gauge valve at the left is opened to provide a passage between
the suction gauge and the center manifold outlet. The discharge gauge valve at the right is opened to provide a
passage between the discharge pressure gauge and the center manifold outlet.
Detailed instructions for proper use of the gauge set manifold are contained in the text covering each test and
service operation employing these gauges.
Suction Gauge; the left side of the manifold set is calibrated to register 0 to-100 kPa (0 to 30 in. of vacuum) and
0 to 1000 kPa (0 to 150 psi). This gauge is connected to the suction port of the compressor.
Discharge Gauge; the right of the manifold set is calibrated to register 0 to 2100 kPa (0 to 300 psi). For all
tests this gauge is connected to the discharge port of the system.
Center Manifold Outlet provides the necessary connection for a long service hose used when discharging the
system, using a vacuum pump to “pull a vacuum” before charging the system, and for connecting the supply of
refrigerant when charging the system
glass -
2OW724 N24FEAE The receiver drier assembly consists of; Drier reservoir, Refriger-
ant level sight glass and Fusible plug.
To Test the Receiver Drier (1) Operate the unit and check the piping temperature by
touching the receiver drier outlet and inlet.
(2) If there is a difference in the temperatures, the
received drier is restricted.
Replace the receiver drier.
SIGHT GLASS REFRlGERANT LEVEL TEST The sight glass is a refrigerant level indicator. To check the refrigerant level, clean the sight glass and start the
vehicle engine. Push the air conditioner button to operate the compressor, place the blower switch to high and
move the temperature lever to extreme left.
After operating for a few minutes in this manner, check the sight glass.
(1) If the sight glass is clear, the magnetic clutch is engaged, the compressor discharge line is warm and the
compressor inlet line is cool; the system has a full charge.
(2) If the sight glass is clear, the magnetic clutch is engaged and there is no significant temperature difference
between compressor inlet and discharge lines; the system has lost some refrigerant.
(3) If the sight glass is clear and the magnetic clutch is disengaged; the clutch is faulty or, the system is out of
refrigerant. Perform low pressure switch test to determine condition. Check low pressure switch and clutch coil
for electrical continuity.
1 STB Revision

24-28 AIR-CONDITIONING-Safety Precautions
SAFETY PRECAUTIONS N24PAAB
SAFETY PRECAUTIONS
I
The refrigerant used in all air-conditioning installations is R-12. It is transparent and colorless in both the liquid and
vapor state. Since it has a boiling point of -29.8T (-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 nonexplosive. It is nonpoisonous
except when it is in direct contact with open flame. It is noncorrosive except when combined with water. The
following precautions must be observed when handling R-12.
Caution
Wear
safety goggles when servicing the refrigeration 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 refrigeration part of the air- conditioning system. Keep a bottle of
sterile mineral oil handy when working on the refrigeration system. Should any liquid refrigerant get into the eyes,
use a few drops of mineral oil to wash them out. RI12 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.
Caution
Do not heat R-12 above 52°C (125°F).
In 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°F) is all the heat required for this purpose. Do not heat the refrigerant container with a blow torch or any other
means that would raise temperature and pressure above this temperature. 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.
Caution
Always work in a well-ventilated room.
Good ventilation is vital in the working area. Always discharge the refrigerant into the service bay exhaust system
or outside the building. Large quantities of refrigerant vapor in a small, poorly ventilated room can displace the air
and cause suffocation.
Although R-12 vapor is normally nonpoisonous, contact with an open flame can cause the vapor to become very
poisonous. Do not discharge large quantities of refrigerant in an area having an open flame. A poisonous gas is
producted when using the flame-type leak detector. Avoid inhaling the fumes from the leak detector.
Caution
Do 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.
/ STB Revision
-I

AIR-CONDITIONING-Service Adjustment Procedures
SERVICE ADJUSTMENT PROCQDURES 24-29 N24FDAD
MANIFOLD GAUGE SET INSTALLATUON Discharge
W gauge
Suction
gauge
Suction
gauge
valve Manifold Gauge Valves should be closed
when connecting the manifold gauge set to the service port of the
compressor and the discharge hose. The suction gauge valve at the left is opened to provide a passage between
the suction gauge and the center manifold outlet. The discharge gauge valve at the right is opened to provide a
passage between the discharge pressure gauge and the center manifold outlet.
Detailed instructions for proper use of the gauge set manifold are contained in the text covering each test and
service operation employing these gauges.
Suction Gauge; the left side of the manifold set is calibrated to register 0 to-100 kPa (0 to 30 in. of vacuum) and
0 to 1000 kPa (0 to 150 psi). This gauge is connected to the suction port of the compressor.
Discharge Gauge; the right of the manifold set is calibrated to register 0 to 2100 kPa (0 to 300 psi). For all
tests this gauge is connected to the discharge port of the system.
Center Manifold Outlet provides the necessary connection for a long service hose used when discharging the
system, using a vacuum pump to “pull a vacuum” before charging the system, and for connecting the supply of
refrigerant when charging the system
glass -
2OW724 N24FEAE The receiver drier assembly consists of; Drier reservoir, Refriger-
ant level sight glass and Fusible plug.
To Test the Receiver Drier (1) Operate the unit and check the piping temperature by
touching the receiver drier outlet and inlet.
(2) If there is a difference in the temperatures, the
received drier is restricted.
Replace the receiver drier.
SIGHT GLASS REFRlGERANT LEVEL TEST The sight glass is a refrigerant level indicator. To check the refrigerant level, clean the sight glass and start the
vehicle engine. Push the air conditioner button to operate the compressor, place the blower switch to high and
move the temperature lever to extreme left.
After operating for a few minutes in this manner, check the sight glass.
(1) If the sight glass is clear, the magnetic clutch is engaged, the compressor discharge line is warm and the
compressor inlet line is cool; the system has a full charge.
(2) If the sight glass is clear, the magnetic clutch is engaged and there is no significant temperature difference
between compressor inlet and discharge lines; the system has lost some refrigerant.
(3) If the sight glass is clear and the magnetic clutch is disengaged; the clutch is faulty or, the system is out of
refrigerant. Perform low pressure switch test to determine condition. Check low pressure switch and clutch coil
for electrical continuity.
1 STB Revision

24-30 AIR-CONDITIONING -Service Adjustunent Procedures
(4) If the sight glass shows foam or bubbles, the systpm could be low on charge. Occasional foam or bubbles are
normal when the ambient temperature is above 43”C(110”F) or below 21”C(7O”F).
Adjust the engine speed to 1,500 rpm. Block the airflow through the condenser to increase the compressor
discharge pressure to 1,422 to 1,520 kPa (20$ to 220 dsi). If sight glass still shows bubbles or foam, system charge
level is low.
The refrigerant system will not be low on charge unless there is a leak. Find and repair the leak. If the leak can be
repaired without discharging the system an oil level check is not necessary. Use the procedure for correcting low
refrigerant level found in the Refrigerant Sy$em Service Procedure Section.
FUSIBLE PLUG
When ambient temperature of the fusible plug reach& 105~221~F), the fusible plug melts and the refrigerant in
the system is released.
Once the fusible plug is operated, it cannot be used again.
SO, it is necessary to install new one and charge the refrigerant in the system.
Low pressure
switch , LOW PRESSURE SWITCH
The Low Pressure Switch, located on the liquid line, is wired in
series with the magnetic clutch. It cuts off the electrical power
supply to the clutch when refrigerant pressure drops below the
cont$ol point of the switch. Whenever the system is inactivated by
the low pressure switch due to refrigerant loss, the refrigerant oil
may have been lost. Therefore, to prevent damage to the com-
pressor due to operation without sufficient lubrication, the leak
must be repaired and the compressor oil level checked before final
charge of the system. The switch is a sealed, factory calibrated
unit. No attempt should be made to adjust or otherwise repair it.
If it is found to be faulty it must be replaced.
To Test the Low Pressure Switch (Engine Off)
(1) Jump the wire leads.
(2) Press the air conditioner switch and blower switch on.
(3) Momentarily turn the ignition switch on (do not crank the en-
gine), listen for the compressor clutch engaging.
(4) If the clutch does not engage, the fin thermostat, water tem-
perature switch or fuse may be faulty.
(5) If clutch engages, connect the manifold gauge set and
read pressure. At pressure of 210 kPa (30 psi) or above,
switch must actuate the clutch.
If the pressure is below 210 kPa (30 psi), the refrigerant
system is low in charge. For corrective action refer to
refrigerant leak repair procedure.
(6) Reconnect boot on switch and perform step number 3.
If the clutch does not engage, discharge the system, replace
the switch, and recharge the system.
[
STB Revision

24-34 AIR-CONDITIONING-Service Adiustment Procedures
r---- :
:ES
Dry bulb therr&neter
2OW825
PEAFORMANCE TEST
TESI N24FWAB NOTE
Air temperature in test room must be 21°C (70°F) minimum for this
test.
(1) Connect a tachometer and manifold gauge set.
(2) Set air conditioner controls to Max air conditioner, tempera-
ture lever on full cool, and blower on high.
(3) Turn engine on 1000 rpm with air conditioner clutch engaged.
(4) Engine should be warmed up with doors, windows, and hood
open.
(5) Insert a thermometer in the left center air conditioner outlet
and operate the engine for 5 minutes.
(6) Note the discharge air temperature.
NOTE
If the clutch cycles, take the reading before the clutch disen-
gages.
Performance Temperature Chart Garage ambient
temperature
21 “C 26.5 “C 32 “C 37.5 “C 40.6 “C (70 “F) (80 “F) (90 “F) (100 “F) (I 05 “F)
Discharge air
temperature
Compressor
discharge pressure
Evaporator suction
pressure
1.7-4.4 “C 1.7-5.0 “C 1.7-5.6 “C 1.7-6.1 “C 1.7-6.7 “C (35-40 “F) (35-41 “F) (35-42 “F) (35-43 “F) (35-44 “F)
928- 1,322 kPa 1.069-1.547 kPa 1,209-1,772 kPa 1,336-1,969 kPa 1,406-2,109 kPa
(132-188 psi) (152-220 psi) (172-252 psi) (190-280 psi) (200-300 psi)
127-148 kPa
131-162 kPa 134-176 kPa 135- 188 kPa 136-194 kPa
(18-21 psi) (18.6-23 psi) (19-25 psi) (19.2-26.8 psi) (19.4-27.6 psi)
REFRIGERANT LEAK REPAIR PROCEDURE N24FnAB
LOST CHARGE If the system has lost all charge due to a leak:
(1) Evacuate the system. (See the procedure).
(2) Charge the system with approximately one pound of refriger-
ant.
(3) Check for leaks.
(4) Discharge the system.
(5) Repair leaks.
(6) Replace receiver drier.
Caution
Refrigerant
leak tester
Replacement filter-drier units must be sealed while in stor-
age. 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 for quick reassembly to
avoid keeping the system open any longer than necessary. (7) Evacuate and charge the system.
LOW CHARGE If the system has not lost all of its refrigerant charge; locate and
tester repair all leaks. If it is necessary to increase the system pressure
up to find the leak (because of an especially low charge) add refrig-
erant. If it is possible to repair the leak without discharging the
refrigerant system, use the procedure for correcting low refriger-
2OUO316 ant level.
1 STB Revision

AIR-CONDITIONING-Service Adiustment Procedures 24-35
CORRECTING LOW REFRIGERANT LEVEL Suction
Discharge gauge
gauge
I \- a/
gauge valve
II II Discharge gauge
Ho water
52°C i 125°F)
2OUO325
Since the refrigeration system is completely sealed, refrigerant level will not be low unless there is a leak in the
system.
Before adding refrigerant when the cause of low level is not known, the system should be tested for leaks.
Assuming that leaks have been corrected without discharging the system, proceed with partial charge.
Install and connect manifold gauge set.
(I) Close both gauge set manifold valves.
(2) Connect the suction gauge test hose to the suction port of the compressor. Connect the discharge gauge test
hose to the discharge port.
(3) Connect one end of long test hose to center manifold outlet, other end to refrigerant dispensing manifold.
(4) Close two dispensing manifold valves and open remaining dispensing manifold valve. Remove protective cap
from opened valve.
(5) Screw a can of R-12 to the opened manifold valve. Be sure gasket is in place and in good condition. Tighten
refrigerant can and manifold locking nut to insure a good seal. Do not overtighten. 8 to 11 Nm (6 to 8 ft.lbs.) is
sufficient if gasket is in good condition.
(6) Turn manifold valve (above the refrigerant can) completely clockwise to puncture the can. This closes the valve
and seals the refrigerant in the can. Caution
Never heat small cans of refrigerant over 52°C (125’F) as they may explode.
(7) Place the refrigerant in a large pan of water heated to 52°C (125°F). Place pan of water containing the refrigerant
can on an accurate scale so the amount of refrigerant added can be weighed. Open the refrigerant manifold
valve. (8) Purge all air from test hoses.
Air in the system will be trapped in the condenser causing abnormally high
discharge pressures and interfering with condensing of the refrigerant.
(9) Slightly loosen both test hoses at the gauge set manifold. Tighten the hoses as soon as the air is purged.
(10)Slightly loosen charging hose connection at gauge set manifold. This will purge air from the charging hose.
Tighten connection as soon as air is purged.
(1l)With vehicle windows open and hood up, operate engine at 1,500 rpm and jump the switch terminals located
on so the clutch will remain engaged.
(12)Place air conditioner control on air conditioner and place the blower switch on high.
(13)lf necessary, block the condenser to maintain a discharge pressure of 1,422 to 1,520 kPa (206 to 220 psi.).
System must be charged through the evaporator suction service ports as follows:
(a) Slowly open the suction service gauge valve.
Meter flow of refrigerant by adjusting the suction service
gauge valve so that pressure registered at the suction service gauge does not exceed 345 kPa (50 psi). Keep refrigerant container upright.
(b) Add refrigerant gas until there is no foam visible at the sight glass.
(c) Close the suction gauge valve. Caution
Too much refrigerant in the system can cause abnormally high discharge pressures. Care must be
used so that the exact recommended amount of refrigerant is added after foam clears in the sight
glass.
(d) Close dispensing manifold valve. Remove test hoses and adapters from the service ports of compressor,
install protective caps at service ports and reconnect wiring. / STB Revision

AIR-CONDITION1 G-Service Adjustment Procedures 24-37
water 2OUO326
(5) Start the vacuum pump and operate until the evaporator suc-
tion gauge registers at least-101 kPa (29.9 in.of vacuum).
If at least-101 kPa (29.9 in. of vacuum) cannot be obtained,
either the system has a leak or the vacuum pump is defective.
Check the vacuum pump. If the pump proves to be functioning
properly, the system has a leak. Charge the system with one
pound of refrigerant. Locate and repair all leaks. Discharge the
refrigerant and evacuate the system.
(6) Continue to operate the pump for at least five minutes.
(7) Close manifold valves. Turn off the vacuum pump and observe
evaporator suction gauge for two minutes. The vacuum level
should remain constant.
If the vacuum level falls off, the system has a leak. Charge the
system with one pound of refrigerant. Locate and repair all
leaks. Discharge the system and repeat evacuation procedure.
CHARGING THE SYSTEM
The refrigerant system must have been evacuated using the pre-
vious procedure before charging. Charge using only R-l 2 refriger-
ant R-l 2 is available in bulk tanks or small cans. Follow the safety
precautions for handling R-12 as listed in the beginning of this
group.
Charging with Small Cans
When using disposable cans of this type, follow carefully the can
manufactures instructions.
Caution
Never use these cans to charge into the high pressure side of
the system (compressor discharge port) or into a system that
is at high temperature, because the high system pressures
could be transferred into the charging can causing it to ex-
plode.
Keep the refrigerant manifold valves capped when not in use.
Keep a supply of extra refrigerant-can-to-refrigerant-manifold gas-
kets on hand so that gaskets can be replaced periodically. This will
insure a good seal without excessive tightening of the can or the
manifold nuts.
(1) Attach center hose from manifold gauge set to refrigerant
dispensing manifold. Turn refrigerant manifold valves com-
pletely counterclockwise so they are fully open. Remove pro-
tective caps from refrigerant manifold.
(2) Screw refrigerant cans into manifold. Be sure manifold-to-can
gasket is in place and in good condition. Tighten can and man-
ifold nuts to 8 to 11 Nm (6 to 8 ft.lbs.)
(3) Turn refrigerant manifold valves completely clockwise to
puncture the cans and close the manifold valves.
/ ST6 Revision