1987 MITSUBISHI MONTERO hood open

CHARGING SYSTEM - Service Adjustment Procedures 8-77
SERVICE ADJUSTMENT PROCEDUREswmAB
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INSPECTION OF THE CHARGING SYSTEM
VOLTAGE DROP TEST OF ALTERNATOR OUTPUT WIRE
This test judges whether or not the wiring (including the fusible
link) between the alternator B terminal and the battery (+) terminal
is sound by the voltage drop method.
Preparation
(1) Turn the ignition switch to “OFF”.
(2) Disconnect the battery ground cable.
(3) Disconnect the alternator output lead from the alternator “B”
terminal.
(4) Connect a DC ammeter (0 to 100 A) in series to the “B”
terminal and the disconnected output lead. Connect the (+)
lead of the ammeter to the “B” terminal and the (-) lead to
the disconnected output wire.
NOTE
Use of a clamp type ammeter that can measure current with-
out disconnecting the harness is preferred. The reason is that
when checking a vehicles that has a low output current due to
poor connection of the alternator “B” terminal, such poor con-
nection is corrected as the “B” terminal is loosened and a test
ammeter is connected in its place and as a result, causes for
the trouble may not be determined.
(5) Connect a digital voltmeter between the alternator “B” termi-
nal and battery (+) terminal. Connect the (+) lead wire of the
voltmeter to the “B” terminal and the (-) lead wire to the
battery (+) terminal.
(6) Connect the battery ground cable.
(7) Leave the hood open.
Test
(1) Start the engine.
(2) Turn on or off the headlights and small lights and adjust the
engine speed so that the ammeter reads 20 A and read off the
voltmeter indication under this condition.
Result
(1) It is okay if the voltmeter indicates the standard value. ’
Standard value : 0.2 V max.
(2) If the voltmeter indicates a value that is larger than the stan-
dard value, poor wiring is suspected, in which case check the
wiring from the alternator “B” terminal to fusible link to bat-
tery (+) terminal. Check for loose connection, color change
due to overheated harness, etc. and correct them before test-
ing again.
(3) Upon completion of the test, set the engine speed at idle. Turn
off the lights and turn off the ignition switch.
(4) Disconnect the battery ground cable.
(5) Disconnect the ammeter and voltmeter that have been con-
nected for the test purpose.
(6) Connect the alternator output wire to the alternator “B” ter-
minal.
(7) Connect the battery ground cable.
( STB Revision

8-78 CHARGING SYSTEM - Service Adiustment Procedures
80A
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Relay with diode
Voltmeter
Ammeter Iad
176
OUTPUT CURRENT TEST
This test judges whether or not the alternator gives an output
current that is equivalent to the nominal output.
Preparation
(1) Prior to the test, check the following items and correct as
necessary.
(a) Check the battery installed in the vehicle to ensure that it
is in sound state*. The battery checking method is de-
scribed in “BATTERY”.
NOTE
*The battery that is used to test the output current should
be one that has been rather discharged. With a fully
charged battery, the test may not be conducted correctly
due to an insufficient load.
(b) Check tension of the alternator drive belt. The belt tension
check method is described in “GROUP 7 COOLING -
Service Adjustment Procedures”.
(2) Turn off the ignition switch.
(3) Disconnect the battery ground cable.
(4) Disconnect the alternator output wire from the alternator “B”
terminal.
(5) Connect a DC ammeter (0 to 100 A) in series between the “B”
terminal and the disconnected output wire. Connect the (+)
lead of the ammeter to the “B” terminal and connect the (-)
lead wire to the disconnected output wire.
NOTE
Tighten each connection by bolt and nut securely as a heavy
current will flow. Do not relay on clips.
(6) Connect a voltmeter (0 to 20 V) between the “B” terminal and
ground. Connect the (+) lead wire to the alternator “B” ter-
minal and (-) lead wire to a sound ground.
(7) Set the engine tachometer and connect the battery ground
cable.
(8) Leave the engine hood open.
Test
(1) Check to see that the voltmeter reads the same value as the
battery voltage.
If the voltmeter reads 0 V, an open circuit in the wire between
the alternator “B” terminal and battery (-) terminal, a blown
fusible link or poor grounding is suspected.
(2) Turn on the headlight switch and start the engine.
(3) Set the headlight at high beam and the heater blower switch
at HIGH, quickly increase the engine speed to 2500 rpm and
read the maximum output current value indicated by the am-
meter.
NOTE
After the engine start up, the charging current quickly drops.
therefore, above operation must be done quickly to read max-
imum current value correctly.
[ STB Revision
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24-34 AIR-CONDITIONING-Service Adiustment Procedures
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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