fuse MITSUBISHI MONTERO 1987 1.G Service Manual

TROUBLESHOOTING
HEATERS -Troubleshooting 24-3
N24EAAC
Reference
Symptom Probable cause Remedy
paw
Improper heat Obstructed floor outlets Correct -
’ Changeover dampers improperly adjusted Correct 24-5
or binding
, Thermostat malfunction
Replace -
Obstructed heater hoses
Replace 24-l 2
’ Improperly adjusted control cables
Adjust 24-5
Plugged or partially plugged heater core
Clean or replace 24-l 3
No ventilation even Incorrect adjustment of changeover dam-
Adjust 24-5
when mode selection pers
lever is operated
Incorrect installation mode selection control
Adjust 24-5
wire
Blower motor oper-
ates on high speed
only
Blower motor inop-
erative Ducts are incorrectly/incompletely con-
netted, crushed, bent or clogged.
Broken blower motor resister
Broken blower switch
Burnt-out fuse
Poor grounding
Malfunction blower switch
Malfunction blower motor Repair or replace
Replace
Replace
Replace
Correct
Replace
Replace -
24-l 5
24-l 0
-
-
24-l 0
24-l 4 1 STB Revision

24-4 HEATERS c Circuit Diagram
CIRCUIT DIAGRAM
I
El3 1 El1
lanition switch
Sub fusible link
Battery link m- (Fuse B)
3
1 I (Ignition switch)
Multi-purpose Q
fuse
M $5
LA,:
a3
To turn sional flasher (Init
0.85RI I I f-Y ’ I [Refer to P.8-49.7- - - ‘d -r i
I Blower
Blower switch
CJ -18
Heater r&v Blower motor ?
resistor
Remark
For information concerning the ground points (example:
q ),
refer to P.8-7.
Wiring color code
B: Black Br. Brown
G: Green
Gr: Gray
LI: Light blue
0: Orange P: Pink
R: Red L: Blue
Y: Yellow Lg: Light green
W: White
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24-22 AIR-CONDITIONING - Special TOOIS / Troubleshooting
SPECIAL TOOLS
Tool (Number and name)
MB990783-01
Steering/pinion gear
remover/installer Use
Installation of seal plate
TROUBLESHOOTING N24EBAE
Before replacing or repairing air conditioning compofents, first determine if the malfunction is; due to refrigerant
charge, air flow, or compressor related.
The following diagnostic charts have been developed as a “quick reference” aid in determining the cause of
malfunction. If these charts do not satisfactorily describe the problem, refer to appropriate section for detailed
explanation.
N24DA.-
After correcting the malfunction, check out the complete system to assure satisfactory performance.
MALFUNCTION CAUSES AND REMEDIES (Numbers indicate checking/inspection order.)
1 not cool 1 Air is
emitted
but is * 1. Magnetic clutch is
not switched ON
SEE NEXT PAGE 1 Replace
1
I
I I
-4 2.Check the fuse (IOA)
t-l Replace
I
I I
I ,
I
3,Check the air-conditioner
__) Replace
switch (P.24-32)
I
4.Check the low pressure
switch (P.24-30) - Replace
---L 5.Check the thermistor
- Replace
and therm0 relay (P.24-31)
- 6.Check the blower
switch (P.24-10) - Replace
-i 7.Check the blower relay
M Replace
(P.24-15)
8.Check the magnetic clutch
(P.24-32) Replace
I
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24-26 AIR-CONDITIONING - Circuit Diagram
CIRCUIT DIAGRAM I N24ZB--
Ignition switch
Main
link Sub fusible link
(Fuse B)
I Battery
3
To turn signal flasher unit ~
0.85-RL [Refer to P.8-49.1
i

I 1 ,0.85-LW F
0.85-WB*
“yl lLG1 [Refer to P.8-62.1
C-C
Blower
motor
M
E!! Blower motor
T IA2
Ml
kFF -18
Heater relav N BI ower switch B L
EEJ LR LR resistor
LB LY
El3 LR LI
x’, $2
Wiring color code
B: Black Br: Brown G: Green
Gr: Gray L: Blue Lg: Light green
LI: Light blue 0: Orange P: Pink R: Red
Y: Yellow W: White
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24-30 AIR-CONDITIONING -Service Adjustunent Procedures
(4) If the sight glass shows foam or bubbles, the systpm could be low on charge. Occasional foam or bubbles are
normal when the ambient temperature is above 43”C(110”F) or below 21”C(7O”F).
Adjust the engine speed to 1,500 rpm. Block the airflow through the condenser to increase the compressor
discharge pressure to 1,422 to 1,520 kPa (20$ 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.
[
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AIR-CONDITIONING-Service Adiustment Procedures 24-31
FREEZE UP CONTROL
Evaporator freeze up is controlled by a thermistor attached to the
evaporator fins. The control is an electronic type and consists of
two parts_(thermo relay and thermistor.) It is connected to the
magnetic clutch of the compressor in series. When the tempera-
ture of the evaporator drops below 3°C (37.4”F), the compressor is
turned OFF.
To Test the Thermistor
(1) Jump the wire lead (LB to GB) of the connector portion.
(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 clutch engaging.
(4) If the clutch does not engage, the low pressure switch,
water temperature switch wiring or fuse may be faulty.
(5) If the clutch operates, replace the thermostat.
WATER TEMPERATURE SWITCH
The water temperature switch is located on the thermostat hous-
ing. The water temperature switch is connected to the clutch
in series. When the coolant temperature in the radiator
reaches above 113°C (235”F), it turns the compressor OFF.
This is to prevent engine overheating.
When the water temperature switch is activated and the clutch is
OFF, check the surface of the condenser and radiator, the belt
tension, and the coolant volume in the radiator, and return to the
normal condition.
To Test the Water Temperature Switch
(1) Remove wire from water temperature switch and jump lead
wires.
(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 clutch engaging.
(4) If the clutch does not-engage, the fin thermistor, low pressure
switch, wiring or fuse may be faulty.
(5) If clutch engages, replace the switch.
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24-32 AIR-CONDITIONING-Service Adjustment Procedures
i--
9 >
@
r
2ouo319
- 2OW627 I
Suction gauge Discharge w-w
/ I
Suction
ww Discharge
w-w
2OUO306
Suction
w-w Discharge
gauge
2OUO307
AIR CONDITIONER SWITCH
To jest the Air Conditioner Switch
(1) Disconnect the harness connector for the air conditioner
switch.
(2) Jump the lead wires as shown.
(3) Turn the blower switch ON.
(4) Momentarily turn the ignition switch on (do not crank the en-
gine), listen for the clutch engaging.
(5) If the clutch does not engage, fin thermostat, water
temperature switch, wiring or fuse may be faulty.
(6) If clutch engages, replace the air conditioner switch.
MAGNETIC CLUTCH
(1) Disconnect the wiring to the magnetic clutch.
(2) Connect battery (+) voltage directly to the wiring for the mag-
netic clutch.
(3) If the magnetic clutch is normal, there will be a “click”. If the
pulley and armature do not make contact (“click”), there is a
malfunction.
COMPRESSOR
(1) Install the manifold gauge set, and run the air conditioner.
(2) If a pressure of approx.490 kPa (71 psi) is indicated on the
suction gauge side and a pressure of approx.883 kPa (128 psi)
is indicated on the discharge gauge side, the compressor has
abnormal compression.
Replace the compressor.
(3) If a pressure of 294 to 392 kPa (43 to 59 psi) is indicated on the
suction gauge side and a pressure of approx.1961 kPa (284
psi) is indicated on the discharge gauge side, it is suspected
that air is present in the air conditioning system.
Discharge the system, evacuate and recharge with specified
amount of refrigerant.
(4) During operation of the air conditioner, cold air may stop flow-
ing after the elapse of time and this state is maintained before
cold air flows out again. If cold air stops flowing out with
negative pressure indicated on the suction gauge side and a
pressure of 588 to 980 kPa (85 to 142 psi) indicated on the
discharge gauge side, it is suspected that water is present in
the air conditioning system.
Discharge the system. Replace receiver drier. Evacuate and
check for leaks, and recharge with specified amount of refrig-
erant.
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