Montero
1) Move temperature selector lever to far left position.
Remove heater control valve cover. Disconnect heater control valve
wire from blend door lever. Push heater control valve inward (closed).\
2) Move blend door lever downward in direction indicated by
arrow. See Fig. 3. Connect inner wire to lever, and secure outer
housing using clip. Adjust heater control valve wire so valve is fully
closed. Operate mode control knob to ensure proper operation.
Reinstall heater control valve cover.
Fig. 3: Adjusting Temperature Selection Cable (Montero)
Courtesy of Mitsubishi Motor Sales of America.
TROUBLE SHOOTING
AIR NOT COOL
1) Ensure compressor clutch is operating. If compressor
clutch is not operating, check fuses and relay. Check A/C switch.
Check high and low pressure switches or dual pressure switch. Check
thermistor, thermo relay or Electronic Cycling Clutch Switch (ECCS).
Check blower switch and relay. Check A/C compressor clutch coil.
2) Ensure system is properly charged with correct amount of
refrigerant. Add refrigerant or evacuate and recharge 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 compressor 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. Add refrigerant or evacuate
and recharge 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.
INTERMITTENT COOL AIR
Check for air or moisture in system. Evacuate and recharge
system as necessary. Check for expansion valve malfunction. Replace
expansion valve if necessary. Check compressor belt for proper
tension.
TESTING
A/C SWITCH
1) Disconnect A/C switch harness connector. Using appropriate
wiring diagram as a guide, jumper appropriate terminals of A/C switch
wiring harness connector. See Fig. 4.
2) Turn blower on and momentarily turn ignition on without
starting engine. Listen for compressor clutch engagement. If
compressor clutch does not engage, check fuse and other components
wired in series with compressor clutch.
Fig. 4: A/C Switch Connector ID
Courtesy of Mitsubishi Motor Sales of America.
AIR THERMO & AIR INLET SENSORS
Fig. 7: Front Blower Switch Terminal ID (Colt Vista & Montero)
Courtesy of Mitsubishi Motor Sales of America.
DUAL PRESSURE SWITCH
Montero, Pickup & Ram-50
1) Turn engine off. Disconnect harness connector at dual
pressure switch (located near condenser). Jumper harness connector.
Turn A/C switch and blower switch to ON positions. Momentarily turn
ignition on and listen for compressor clutch engagement.
2) If compressor clutch does not engage, check evaporator
thermistor and engine coolant temperature switch. Check for a faulty
fuse. Repair or replace components as necessary. If compressor clutch
engages, go to next step.
3) Connect manifold gauge set to system, and check operating
pressures. Dual pressure switch should allow compressor operation if
system pressure is 30-384 psi (2-27 kg/cm
). If dual pressure switch
does not operate within specified pressure range, discharge system
using approved refrigerant recovery/recycling equipment, and replace
switch.
4) After replacing switch, recharge system, and monitor
pressures for proper compressor operation. If dual pressure switch
cuts power to compressor clutch while driving even though temperatures
inside have not yet decreased, high pressure side of dual pressure
switch has possibly been activated. Go to next step.
5) Discharge system using approved refrigerant
recovery/recycling equipment. Replace switch, and recharge system.
Ensure compressor clutch operates within 30-384 psi (2-27 kg/cm
).
Check for sufficient system cooling.
ENGINE COOLANT TEMPERATURE SWITCH
1) Turn engine off. Disconnect connector at engine coolant
temperature switch. Jumper wires on harness side of connector. If
vehicle uses a single connector, ground connector.
2) Press A/C switch to ON position and turn blower switch to
ON position. Momentarily turn ignition on and listen for compressor
clutch engagement. Clutch should engage. If clutch does not engage,
check fuse and other components wired in series with compressor
clutch.
EVAPORATOR THERMISTOR
Disconnect connector and remove thermo relay from evaporator
core. Jumper wires on harness side connector. Turn A/C switch to ON
position and turn on blower. Momentarily turn ignition on and listen
for compressor clutch engagement. If clutch does not engage, check
fuse and other components wired in series with compressor clutch.
HIGH PRESSURE SWITCH
Colt Vista
Disconnect high pressure switch connector. Jumper wires on
harness side of connector. Momentarily turn ignition on and listen for
compressor clutch engagement. If clutch does not engage, check fuse
and other components wired in series with compressor clutch.
HIGH/LOW PRESSURE CUT-OFF SWITCH
Pickup & Ram-50
1) Turn engine off. Disconnect High/Low Pressure Cut-Off
(HLPCO) switch, located on refrigerant line near condenser. Jumper
HLPCO wiring harness connector. Turn A/C switch and blower switch to
ON positions. Momentarily turn ignition on and listen for compressor
clutch engagement.
2) If compressor clutch does not engage, check evaporator
thermistor and engine coolant temperature switch. Check for a faulty
fuse. Repair or replace as necessary. If compressor clutch engages, go
to next step.
3) Connect manifold gauge set to system, and check operating
pressures. HLPCO switch should allow compressor operation if system
pressure is 28-385 psi (1.9-27 kg/cm
). If HLPCO switch does not
operate within specified pressure range, discharge system using
approved refrigerant recovery/recycling equipment, and replace switch.
4) After replacing switch, recharge system, and monitor
pressures for proper compressor function. If HLPCO switch cuts power
to compressor clutch while driving even though temperatures inside
have not yet decreased, high pressure side of new HLPCO switch has
possibly been activated. Go to next step.
5) Discharge system using approved refrigerant
recovery/recycling equipment. Replace switch, and recharge system.
Ensure compressor clutch operates within 28-385 psi (1.9-27 kg/cm
).
Check for sufficient system cooling.
LOW PRESSURE SWITCH
Colt Vista
Disconnect low pressure switch connector. Jumper wires on
harness side of connector. Momentarily turn ignition on and listen for
compressor clutch engagement. If clutch does not engage, check fuse
and other components wired in series with compressor clutch.
\003
* A /C -H EA TE R S YSTE M U NIF O RM IN SPEC TIO N G UID ELIN ES *
1 991 M it s u bis h i M onte ro
GENERAL INFORMATION
A/C-Heater System Motorist Assurance Program
Standards For Automotive Repair
All Makes and Models
INTRODUCTION TO MOTORIST ASSURANCE PROGRAM (MAP)
CONTENTS
Motorist Assurance Program (MAP)
OVERVIEW
OVERVIEW OF SERVICE REQUIREMENTS & SUGGESTIONS
Heating, Ventilation and Air Conditioning
ACCUMULATORS
ACTUATORS (ELECTRICAL)
ACTUATORS (VACUUM)
AIR CONDITIONING FITTINGS
AIR CONDITIONING HOSES
AIR CONDITIONING METAL LINES, HOSES AND FITTING ASSEMBLIES
AIR CONTROL DOORS
AIR DAMS (EXTERNAL)
AIR DISTRIBUTION SYSTEM
BELTS
BLEND DOORS
BLOWER FANS (BLOWER WHEEL OR SQUIRREL CAGE)
BLOWER MOTORS
BLOWER RESISTORS
BLOWER SWITCHES
CABIN AIR FILTERS
CIRCUIT BREAKERS
COMPRESSOR CLUTCH ASSEMBLIES
COMPRESSORS
CONDENSER AIR SEALS
CONDENSER FAN MOTORS
CONDENSERS
CONNECTORS
CONTROL CABLES
CONTROL HEADS (FUNCTION SELECTORS)
CONTROL LINKAGES
CONTROL MODULES
COOLANT
COOLING FAN BLADES
COOLING FAN CLUTCHES
COOLING FAN MOTORS
EVAPORATOR DRAIN TUBES
EVAPORATOR PRESSURE REGULATORS (EPRS)
EVAPORATORS
EXPANSION VALVES
FUNCTION SELECTORS
FUSES, FUSIBLE LINKS AND CIRCUIT BREAKERS
FUSIBLE LINKS
GASKETS
HEATER CASES
HEATER CONTROL VALVES
HEATER CORES
or the vehicle manufacturer's recommended service interval and must be
documented.
Some conditions indicate that service or part replacement is
required because the part in question is no longer providing the
function for which it is intended, does not meet a vehicle
manufacturer's design specification or is missing.
Example:
An exhaust pipe has corroded severely and has a hole in it
through which exhaust gases are leaking. Replacement of the
exhaust pipe in this case is required due to functional
failure.
Example:
A brake rotor has been worn to the point where it measures
less than the vehicle manufacturer's discard specifications.
Replacement of the rotor is required because it does not meet
design specifications.
Some conditions indicate that a service or part replacement
is suggested because the part is close to the end of its useful life
or addresses a customer's need, convenience or request. If a
customer's vehicle has one of these conditions, the procedure may be
only to suggest service.
Example:
An exhaust pipe is rusted, corroded or weak, but no leaks are
present. In this case, the exhaust pipe has not failed.
However, there is evidence that the pipe may need replacement
in the near future. Replacement of the pipe may be suggested
for the customer's convenience in avoiding a future problem.
Example:
The customer desires improved ride and/or handling, but the
vehicle's shocks or struts have not failed. In this case,
replacement may be suggested to satisfy the customer's
wishes. In this case, replacement of the shocks or struts may
not be sold as a requirement.
A customer, of course, has the choice of whether or not a
shop will service his or her vehicle. He or she may decide not to
follow some of your suggestions. When a repair is required, a MAP shop
must refuse partial service on that system if, in the judgment of the
service provider, proceeding with the work could create or continue an
unsafe condition. When a procedure states that required or suggested
repair or replacement is recommended, the customer must be informed of
the generally acceptable repair/replacement options whether or not
performed by the shop.
When presenting suggested repairs to the customer, you must
present the facts, allowing the customer to draw their own conclusions
and make an informed decision about how to proceed.
The following reasons may be used for required and suggested
services. These codes are shown in the "Code" column of the MAP
Uniform Inspection & Communications Standards that follow:
Reasons to Require Repair or Replacement
A - Part no longer performs intended purpose
B - Part does not meet a design specification (regardless of
performance)
C - Part is missing
NOTE: When a repair is required, the shop must refuse partial
Connector missing ....... C ............ Require replacement.
Inoperative ............. A ........ (2) Require replacement.
Insulation overheated ... A ............ Require 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.
( 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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BLOWER SWITCHES
See SWITCHES.
CABIN AIR FILTERS
CABIN AIR FILTER INSPECTION \
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Condition Code Procedure
Air flow obstruction .... A ............. Require cleaning or
replacement.
Maintenance intervals ... 3 ............ Suggest replacement.
Missing ................. C ............ Require replacement.
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CIRCUIT BREAKERS
See FUSES, FUSIBLE LINKS AND CIRCUIT BREAKERS .
COMPRESSOR CLUTCH ASSEMBLIES
COMPRESSOR CLUTCH ASSEMBLY INSPECTION \
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Condition Code Procedure
Air gap incorrect ....... B .. Require repair or replacement.
Bearing seized .......... A .. Require replacement of bearing
or assembly.
Bearing worn, affecting
performance ............ A .. Require replacement of bearing
or assembly.
Coil shows signs of
overheating ............ 1 .... Suggest replacement of coil.
Connector broken ........ A .. Require repair or replacement.
Connector (Weatherpack
type) leaking .......... A .. Require repair or replacement.
Connector melted,
(such as compression
fitting) ............... B ............ Require replacement.
Flange leaking .......... A .. Require repair or replacement.
Leaking ................. A .. Require repair or replacement.
Restricted internally ... A .. Require repair or replacement.
Threads damaged ......... A .. Require repair or replacement.
Threads stripped (threads
missing) ............... A ............ Require replacement.
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EXPANSION VALVES
EXPANSION VALVE INSPECTION \
\
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Condition Code Procedure
Application incorrect ... B ............ Require 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.
Corroded internally ..... 1 ............ Suggest replacement.
Filter screen torn ...... A .. Require replacement of screen.
Inoperative ............. A ........... ( 1) Require repair or
replacement.
Leaking ................. A ............ Require replacement.
Restricted .............. A .. Require repair or replacement.
Threads damaged ......... A .. Require repair or replacement.
Threads stripped (threads
missing) ............... A ............ Require replacement.
( 1) - Expansion valve operation may be affected by capillary
tube location, corrosion, and insulation tape.
Inoperative includes intermittent operation.
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FUNCTION SELECTORS
See CONTROL HEADS (FUNCTION SELECTORS) .
FUSES, FUSIBLE LINKS AND CIRCUIT BREAKERS
FUSE, FUSIBLE LINK AND CIRCUIT BREAKER INSPECTION \
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Condition Code Procedure
Application incorrect ... B ............ Require replacement.
Blown ................... A ........ ( 1) Require replacement.
Corroded, affecting
performance ............ A .. Require repair or replacement.
Corroded, not affecting
performance ............ 2 .. Suggest repair or replacement.
Cracked, affecting
performance ............ A .. Require repair or replacement.
Cracked, not affecting
performance ............ 1 .. Suggest repair or replacement.
Inoperative ............. A ... ( 2) Require replacement.
Insulation damaged,