1998 MITSUBISHI MONTERO Service Manual

Bracket cracked, not
affecting performance .. 1 .. Suggest repair or replacement.
Bracket holes elongated,
affecting performance .. A .. Require repair or replacement.
Bracket holes elongated,
not affecting
performance ............ .. ........ No service suggested or
required.
Bracket loose, affecting
performance ............ A .. Require repair or replacement.
Bracket loose, not
affecting performance .. 1 .. Suggest repair or replacement.
Bracket missing ......... C ............ Require replacement.
Connection damaged ...... B .. Require repair or replacement.
Contaminated, affecting
performance ............ A ............ Require replacement.
Corroded internally ..... 1 ............ Suggest replacement.
Dessicant bag
deteriorated ........... A ........ (1) Require replacement.
Further inspection required.
Dessicant at the end of
its useful life
(saturated
with moisture) ......... 1 .. Suggest repair or replacement.
Filter screen torn ...... A .. Require replacement of screen.
Fitting damaged ......... B .. Require repair or replacement.
Fusible plug leaking .... A .... Require replacement of plug.
Inoperative ............. A ........... ( 2) Require repair or
replacement.
Leaking ................. A .. Require repair or replacement.
Pressure relief device
leaking ................ A . Require replacement of pressure
relief device.
Restricted .............. A .. Require repair or replacement.
Sight glass no longer
transparent ............ 2 ... Suggest replacement of drier.
Threads damaged ......... A .. Require repair or replacement.
Threads stripped (threads
missing) ............... A ............ Require replacement.
Tubing connection
leaking ................ A .. Require repair or replacement.
( 1) - Inspect system to determine effects of dessicant bag
deterioration.
( 2) - Inoperative includes intermittent operation or out of
OEM specification.









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WATER PUMPS (ELECTRIC AUXILIARY)
WATER PUMP (ELECTRIC AUXILIARY) INSPECTION








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Condition Code Procedure
Attaching hardware
broken ................. A ... Require repair or replacement
of hardware.
Attaching hardware
missing ................ C .......... Require replacement of
hardware.
Attaching hardware not
functioning ............ A ... Require repair or replacement
of hardware.

Connector broken ........ A .. Require repair or replacement.
Connector (Weatherpack
type) leaking .......... A .. Require repair or replacement.
Connector melted,
affecting performance .. A ........... (1) Require repair or
replacement.
Connector melted, not
affecting performance .. 2 ........... ( 1) Suggest repair or
replacement.
Connector missing ....... C ............ Require replacement.
Inoperative ............. A ........ ( 2) Require replacement.
Leaking ................. A .. Require repair or replacement.
Missing ................. C ............ Require replacement.
Noisy ................... 2 ............ Suggest replacement.
Terminal broken ......... A .. Require repair or replacement.
Terminal burned, affecting
performance ............ A ........... ( 1) Require repair or
replacement.
Terminal burned, not
affecting performance .. 2 .. Suggest repair or replacement.
Terminal corroded,
affecting performance .. A .. Require repair or replacement.
Terminal corroded, not
affecting performance .. 2 .. Suggest repair or replacement.
Terminal loose, affecting
performance ............ B .. Require repair or replacement.
Terminal loose, not
affecting performance .. 1 .. Suggest repair or replacement.
Vibration ............... 1 .. Suggest replacement.
Wire lead conductors
exposed ................ B .. Require repair or replacement.
Wire lead corroded ...... A .. Require repair or replacement.
Wire lead open .......... A .. Require repair or replacement.
Wire lead shorted ....... A .. Require repair or replacement.
( 1) - Determine cause and correct prior to repair or
replacement of part.
( 2) - Inoperative includes intermittent operation or out of
OEM specification.









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WIRING HARNESSES AND CONNECTORS
WIRING HARNESS AND CONNECTOR INSPECTION








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Condition Code Procedure
Application incorrect ... B .. Require repair or replacement.
Attaching hardware
broken ................. A ... Require repair or replacement
of hardware.
Attaching hardware
missing ................ C .......... Require replacement of
hardware.
Attaching hardware not
functioning ............ A ... Require repair or replacement
of hardware.
Connector broken ........ A .. Require repair or replacement.
Connector (Weatherpack
type) leaking .......... A .. Require repair or replacement.
Circuit open ............ A .. Require repair or replacement.
Circuit resistance
(voltage drop) out of

specification .......... A .. Require repair or replacement.
Circuit shorted ......... A .. Require repair or replacement.
Connector melted,
affecting performance .. A ........... (1) Require repair or
replacement.
Connector melted, not
affecting performance .. 2 ........... ( 1) Suggest repair or
replacement.
Connector missing ....... C ............ Require replacement.
Diode open .............. A .. Require repair or replacement.
Diode shorted ........... A .. Require repair or replacement.
Insulation damaged,
conductors exposed ..... A .. Require repair or replacement.
Insulation damaged,
conductors not exposed . 1 ............ Suggest replacement.
Protective shield
(conduit) melted ....... B ........ ( 1) Require replacement.
Protective shield
(conduit) missing ...... C ............ Require replacement.
Routed incorrectly ...... B ................. Require repair.
Secured incorrectly ..... B ................. Require repair.
Terminal broken ......... A .. Require repair or replacement.
Terminal burned, affecting
performance ............ A ........... ( 1) Require repair or
replacement.
Terminal burned, not
affecting performance .. 2 .. Suggest repair or replacement.
Terminal corroded,
affecting performance .. A .. Require repair or replacement.
Terminal corroded, not
affecting performance .. 2 .. Suggest repair or replacement.
Terminal loose, affecting
performance ............ B .. Require repair or replacement.
Terminal loose, not
affecting performance .. 1 .. Suggest repair or replacement.
Voltage drop out of
specification .......... A .. Require repair or replacement.
( 1) - Determine cause and correct prior to repair or
replacement of part.









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A/C-HEATER SYSTEM
1998 Mitsubishi Montero
1998 AIR CONDITIONING & HEAT
Mitsubishi - A/C-Heater System
Montero
* PLEASE READ THIS FIRST *
WARNING: To avoid injury from accidental air bag deployment, read and
carefully follow all SERVICE PRECAUTIONS and DISABLING &
ACTIVATING AIR BAG SYSTEM procedures in AIR BAG RESTRAINT
SYSTEM article.
A/C SYSTEM SPECIFICATIONS
A/C SYSTEM SPECIFICATIONS TABLE








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Application Specification
Compressor Type ............... Nippondenso 10PA15 10-Cyl.
Compressor Belt Deflection ( 1)
New .......................... 13/64-15/64" (5.1-6.0 mm)
Used ......................... 17/64-19/64" (6.6-7.5 mm)
Compressor Oil Capacity ..................... ( 2) 2.7 ozs.
Refrigerant (R-134a) Capacity ................. 21-23 ozs.
System Operating Pressures ( 4)
High Side ............... 149-213 psi (10.5-15.0 kg/cm
)
Low Side .................... 14-33 psi (1.0-2.3 kg/cm)
( 1) - With 22 lbs. (100 N.m) force applied midway on longest
span of belt.
( 2) - Use ND 8-OIL refrigerant oil.
( 3) - Use SUN PAG 56 refrigerant oil.
( 4) - With ambient temperature at about 80
F (27C).








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DESCRIPTION
Slight variations exist among manual A/C-heater systems used.
On Montero, a Nippondenso 10-cylinder compressor is used. Cycling of
compressor clutch is controlled by an automatic A/C Control Unit
(ACCU).
Compressors will only operate within normal temperatures and
pressures set for each model. An electric condenser fan operates
whenever A/C system is operating. System components may vary depending
upon model. Systems may include an ACCU, fan switch, evaporator,
temperature sensor, dual-pressure switch, engine coolant temperature
switch, compressor, condenser, receiver-drier and various pipes and
hoses.
OPERATION
A/C CONTROL UNIT (ACCU)
ACCU controls cycling of compressor clutch based on
information received from air thermosensor and air inlet sensor, dual-
pressure switch, A/C switch and A/C engine coolant temperature switch.
ACCU is attached to top of evaporator housing.

A/C SWITCH
When turned on, the A/C system will operate if blower motor
control lever is in a position other than OFF. When activated, A/C
switch allows A/C compressor clutch to engage and operate the
compressor.
A/C ENGINE COOLANT TEMPERATURE SWITCH
The A/C engine coolant temperature switch, located on
thermostat housing, is wired in series with compressor clutch. When
coolant temperature is greater than switch control temperature, power
to compressor is cut and compressor is turned off until temperature
returns to operating range. Switch will turn on at 226
F (108C) and
off at 235-243F (112-118C).
AIR SELECTOR LEVER
The lever moves horizontally to select source of air used
inside passenger compartment. Lever moves from position on left
(outside air mode) to position on right (recirculated air mode). Lev\
er
should be set in recirculated air mode for maximum A/C cooling.
BLOWER MOTOR CONTROL SWITCH
Blower motor control switch rotates to select blower motor
speeds. As switch is rotated from left or OFF position, increasing
speeds of blower operation are selected. In order for A/C system to
operate, blower motor control switch must be in a position other than
OFF.
MODE SELECTOR KNOB
Mode selector knob has six modes available to achieve desired
distribution of air from various outlets. When knob is rotated fully
to left (counterclockwise), airflow is directed to upper passenger
area. In second position (clockwise), airflow is directed to upper
passenger area and slightly to leg area. Position 3, directs air
mostly to leg area and slightly to upper passenger area. Position 4,
directs air exclusively to leg area. Position 5, directs air to leg
area and to windshield and door windows. Position 6, directs air
exclusively to windshield and door windows.
TEMPERATURE CONTROL KNOB
Temperature control knob operates blend-air door in
heater/air conditioning unit, mixing cooled and heated air so that
selected air temperature can be obtained. The system will provide
cooled air when A/C switch is in ON position and blower motor is in
any position other than OFF. Temperature control knob should be on far
left (maximum cooling) side of temperature selection scale when
maximum A/C cooling is desired.
DUAL-PRESSURE SWITCH
The dual-pressure switch, mounted on receiver-drier, is wired
in series with compressor clutch. Whenever system pressures drop below
or increase above control points of switch, power supplied to
compressor will be cut and compressor function will cease until
pressures are back to normal operating ranges.

ADJUSTMENTS
NOTE: For adjustment procedures, see HEATER SYSTEM article.
TROUBLE SHOOTING
NO COOLING
1) Ensure compressor clutch is operating. If compressor
clutch is operating, go to next step. If compressor clutch is not
operating, check fuses and A/C switch. Check dual-pressure switch.
Check air inlet sensor and air thermosensor. Check A/C compressor
relay. Check A/C compressor clutch coil. Check A/C control unit.
2) Ensure system is properly charged with correct amount of
refrigerant. Evacuate and charge system as necessary. Ensure receiver-
drier is not clogged. Check compressor belt for proper tension. Check
for clogged expansion valve. Check compressor operation. Repair or
replace components as necessary.
INSUFFICIENT AIRFLOW
Check for air leakage at air duct joint. Check for frost on
evaporator. Ensure blower motor is operating properly. Check for
obstructed air intake.
INSUFFICIENT COOLING
Ensure system is properly charged with correct amount of
refrigerant and free of air and moisture. Evacuate and charge system
as necessary. Ensure receiver-drier is not clogged. Ensure sufficient
airflow through condenser exists. Check compressor belt for proper
tension. Check compressor operation. Repair or replace compressor as
necessary. Check for clogged expansion valve. Replace expansion valve
as necessary. Check A/C compressor clutch coil.
INTERMITTENT COOL AIR
Check for air or moisture in system. Evacuate and charge
system as necessary. Check for expansion valve malfunction. Replace
expansion valve if necessary. Check compressor belt for proper
tension.
TESTING
* PLEASE READ THIS FIRST *
WARNING: To avoid injury from accidental air bag deployment, read and
carefully follow all SERVICE PRECAUTIONS and DISABLING &
ACTIVATING AIR BAG SYSTEM procedures in AIR BAG RESTRAINT
SYSTEM article.
NOTE: For testing procedures not covered in this article, see
HEATER SYSTEM article.
A/C SYSTEM PERFORMANCE
1) Park vehicle out of direct sunlight. Install A/C gauge
set. Start engine and allow it to idle at 1000 RPM. Turn A/C on. Set
A/C controls to recirculated air, panel (vent) mode and full cold

settings.
2) Set blower/fan on high speed. Close doors and windows.
Insert thermometer in center vent. Operate system for 20 minutes to
allow system to stabilize. Measure temperature.
3) Discharge air temperature must be 37-44
F (3-7C) at
center vent, with high side and low side pressures within
specification. See A/C SYSTEM SPECIFICATIONS table at beginning of
article.
A/C CONTROL UNIT (ACCU)
1) Locate A/C Control Unit (ACCU) on top of evaporator case
and disconnect 10-pin connector. Inspect connector and wiring for
damage. Turn ignition and A/C on. Set temperature control to maximum
cooling and blower switch to high. Using a DVOM set to appropriate
test function, inspect harness side of connector. See Fig. 3. Go to
next step. If all test readings are as specified, replace ACCU.
2) Terminal No. 1 (Green/Yellow wire) is ACCU output. With
A/C and blower motor on, battery voltage should be present when ACCU
has received signals from pressure and temperature sensors confirming
A/C operation is okay.
3) Terminal No. 3 (Green/Blue wire) is ACCU power supply whe\
n
A/C switch is in A/C mode. With ignition and blower on, and A/C switch
at second level setting, battery voltage should be present.
4) Terminal No. 5 (Green/Red wire) is ACCU power supply when\
A/C switch is in ECONO mode. With ignition and blower on, and A/C
switch at first level setting, battery voltage should be present.
Terminals No. 2 and 7 (Black wire) are ACCU grounds. There should be
zero volts at all times.
5) Turn ignition off. Reconnect 10-pin connector. Turn
ignition on. Turn A/C on. Set temperature control to maximum cooling
and blower switch to high. Backprobe 10-pin connector. Go to next
step. If all test readings are as specified, replace ACCU.
6) Terminal No. 10 (Blue/White wire) is air thermosensor
power supply. With ignition, blower and A/C on, approximately 5.5
volts should be present.
7) Terminal No. 8 (Blue/Yellow wire) is air thermosensor
signal. When temperature of evaporator outlet portion is 77
F (25C),
there should be approximately 3.6 volts present.
8) Terminal No. 4 (White/Blue wire) is air inlet sensor powe\
r
supply. With ignition, blower and A/C on, approximately 5.5 volts
should be present.
9) Terminal No. 9 (Yellow/Green wire) is air inlet sensor
signal. When temperature of evaporator outlet portion is 77
F (25C),
there should be approximately 1.5 volts present.
Fig. 1: Testing ACCU
Courtesy of Mitsubishi Motor Sales of America.
A/C SWITCH

With A/C switch in indicated position, ensure continuity
exists between listed terminals. See appropriate A/C SWITCH CONTINUITY
TEST table. See Fig. 2.
A/C SWITCH CONTINUITY TEST TABLE









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Switch Position Terminal No. Continuity
OFF ...................... ( 1) ...................... No
ECONO ................... 1 & 3 .................... Yes
A/C ................... 1, 3 & 4 ................... Yes
( 1) - Continuity should not exist between any terminals.









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Fig. 2: Identifying A/C Switch Terminals
Courtesy of Mitsubishi Motor Sales of America.
A/C ENGINE COOLANT TEMPERATURE SWITCH
1) Disconnect A/C engine coolant temperature switch
connector. Remove A/C engine coolant temperature switch. Carefully
heat a pan of oil and hold coolant temperature switch up to threads in
oil. Coolant switch is normally closed (continuity exists).
2) When oil reaches 235-243
F (112-118C), coolant switch
should open (no continuity). Replace A/C engine coolant temperature
switch if it does not test as specified. See Fig. 3.