engine ISUZU KB P190 2007 Workshop Owner's Manual

HEATER AND AIR CONDITIONING 1-53
Checking and Adjusting for Compressor
Replacement
180 cm3 (5.07 lmp fl oz) of oil is charged in compressor
(service parts). So it is necessary to drain the proper amount
of oil from the new compressor.
1) Perform oil return operation.
2) Discharge refrigerant and remove the compressor.
3) Drain the compressor oil and measure the extracted oil.
4) Check the compressor oil for contamination.
5) Adjust oil level as required.
Amount of oil drained
From used compressor Draining amount of oil
From new compressor
less than
90 cm
3 (2.53 lmp fl oz) Some as drained
amount
more than
90 cm
3 (2.53 lmp fl oz) 90 cm
3 (2.53 lmp fl oz)

6) Evacuate, charge and perform oil return operation.
7) Check system operation.


CONTAMINATION OF COMPRESSOR OIL
Unlike engine oil, no cleaning agent is added to the
compressor oil. Even is the compressor runs for a long period
of time (approximately 1 season), the oil never becomes
contaminated as long as there is nothing wrong with the
compressor or its method of use.
Inspect the extracted oil for any of the following
conditions:
• The capacity of the oil has increased.
• The oil has changed color to red.
• Foreign substances, metal powder, etc., are present in the
oil.
If any of these conditions exists, compressor oil is
contaminated. Whenever contaminated compressor oil is
discovered, the receiver/drier must be replaced.


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ISUZU KB P190 2007

1-54 HEATER AND AIR CONDITIONING
OIL RETURN OPERATION
There is close affinity between the oil and the refrigerant.
During normal operation, part of the oil recirculates with the
refrigerant in the system.
W hen checking the amount of oil in the system, or replacing
any component of the system, the compressor must be run in
advance for oil return operation. The procedure is as follows:
1) Open the all doors and engine hood.
2) Start the engine and A/C switch is "ON" and Set the fan control knob at its highest position.
3) Run the compressor for more than 20 minutes between 800 and 1,000 rpm in order to operate the system.
4) Stop the engine.


REPLACEMENT OF COMPONENT PARTS
W hen replacing system component parts, supply the following
amount of oil to the component parts to be installed.
Component parts to be installed Amount of oil
Evaporator 50 cm3 (1.41 lmp fl oz)
Condenser 30 cm3 (0.84 lmp fl oz)
Receiver/drier 30 cm3 (0.84 lmp fl oz)
Refrigerant line (One piece) 10 cm3 (0.28 lmp fl oz)

Refrigeration oil must be replenished if more than two parts
are removed at the same time. After installing these
components, check compressor oil.



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ISUZU KB P190 2007

HEATER AND AIR CONDITIONING 1-55
DISASSEMBLY






This illustration is based on the 4J engine model

RTW 510MF000301

Disassembly Steps
1. Drive plate bolt
2. Plain washer
3. Drive plate
4. Snap ring
5. Pulley assembly
6. Snap ring
7. Field coil
8. Compressor

Important Operations - Disassembly


RTW 510SH000701

1. Drive Plate Bolt
Using drive plate holder to prevent the drive plate from rotating, then remove the bolt.
Drive Plate Holder: 5-8840-4056-0 (J-37872)







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HEATER AND AIR CONDITIONING 1-57
REASSEMBLY






This illustration is based on the 4J engine model

RTW 510MF000401

Reassembly Steps
1. Compressor
2. Field coil
3. Snap ring
4. Pulley assembly
2. Snap ring
3. Drive plate
7. Plain washer
8. Drive prate bolt




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1-86 HEATER AND AIR CONDITIONING
BLOWER MOTOR DOES NOT RUN


Replace
YES
• Is No.SBF-6 (30A) (except C24SE) or No.SBF-8
(30A) (C24SE) slow blow fuse OK?
• Is heater & A/C relay (X-11) OK?
YES
• Is resistor OK?
YES
• Is fan control knob (Fan switch) OK?
YES
YES
• Check to see if battery voltage is present at
chassis side connector terminal No.C105-1 is there a
battery voltage?
• Turn the ignition switch "ON" (Engine is running)
• Fan control knob (Fan switch) "ON"
• Is blower motor OK?
YES
Open circuit either between chassis side connector
terminal No.C105-2 and No.C104-3 or No.B13-1 and
body ground No.C-109.
NO
Replace
NO
Replace
NO
NO
Replace control lever
assembly
Replace
NO
NO
Open circuit between
No.SBF-6 (30A) (except
C24SE) or No.SBF-8 (30A)
(C24SE) slow blow fuse and
No.C105-1.


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1-90 HEATER AND AIR CONDITIONING
f06r300014
CHECKING REFRIGERANT SYSTEM
WITH MANIFOLD GAUGE
Conditions;
• Ambient temperature at approx. 30 ∼35 °C (86 ∼95 °F)
• Run the engine at Idling
• A/C switch is “ON”
• Run the blower motor at “4” (high) position
• Temperature control knob sets at “MAX COLD”
• Air source selector lever at “CIRC”
• Close the all doors
Normal pressures kPa (kg/cm
2 /psi);
Low-pressure side: Approx. 127 – 245 (1.3 – 2.5 / 18 – 36)
High-pressure side: Approx. 1373 – 1670 (14 – 17 / 199 – 242)
Connect the manifold gauge
Low-pressure hose (LOW ) ∼ Suction side
High-pressure hose (HI) ∼ Discharge side



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HEATER AND AIR CONDITIONING 1-93
MAGNETIC CLUTCH
W hen the A/C switch and the fan control knob (fan switch) are turned on with the engine running, current flows
through the thermostat and the compressor relay to activate the magnetic clutch.
The air conditioning can be stopped by turning off the A/C switch or the fan control knob (fan switch).
However, even when the air conditioning is in operation, the electronic thermostat, the pressure switch or the ECM
is used to stop the air conditioning temporarily by turning off the magnetic clutch in the prearranged conditions to
reduce the engine load which is being caused by the rise in the engine coolant temperature, and the acceleration of
the vehicle, etc.


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HEATER AND AIR CONDITIONING 1-95
MAGNETIC CLUTCH DOES NOT RUN (4JA1-T)



Replace
YES
• Are the A/C thermo (X-15) and heater & A/C (X-11)
relay OK?
• Are the No. SBF-6 fuse (30A) and the No. EB-13
(10A) fuses OK?
YES
• Is the pressure switch (C-24) OK?
YES
• Are the A/C switch (B-57) and the fan switch (B-13)
OK?
NO
YES
• Turn the ignition switch "ON" (Engine is running)
• A/C switch and fan control knob (fan switch) "ON"
NO
Replace
NO
Defective switch or insufficient
refrigerant
NO
NO
Does the magnetic clutch
operate?
YES
Replace
• Disconnect the magnetic clutch connector.
• Is there battery voltage between the engine room harness
connector terminal No.1 (E-3) and ground?
Defective compressor
YESNO
Defective magnetic clutch
• Is the electronic thermostat (C-55) OK?
YES
Replace
NO
• Disconnect the A/C thermo relay.
• Is there continuity between the engine room harness
connector terminal No.1 (E-3) and engine room harness
connector terminal No.1 (X-15)?


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ISUZU KB P190 2007

1-96 HEATER AND AIR CONDITIONING




Open circuit between the engine room
harness connector terminal No.1 (X-
15).
NOYES
• Is there continuity between the engine room
harness connector terminal No.2 (X-15) and
ground?
YES
• Is there battery voltage between the engine room
harness connector terminal No.3 (X-15) and
ground? Open circuit between the engine room
harness connector terminal No. 2 (X-
15).
NO
YES
• Is there continuity between the engine room
harness connector terminal No. 5 (X-15) and the
engine room harness connector terminal No. 2 (C-
24)?
Open circuit between the No. EB-13
fuse and the engine room harness
connector terminal No. 3 (X-15).
NO
• Disconnect the pressure switch.
• Disconnect the condenser fan relay connector
condenser fan.
• Is there battery voltage between the engine room
harness connector terminal No.4 (C-24) and
ground? Open circuit between the condenser
fan relay No. 3 (X-13) and engine
room harness connector terminal No.3
(C-24).
• Is there continuity between the relay terminal
No.3 (X-13)and engine room harness connector
terminal No.3 (C-24)?
Open circuit between the engine room
harness connector terminal No. 5 (X-
15) and the engine room harness
connector terminal No. 2 (C-24).
YES NO
YES NO



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ISUZU KB P190 2007

HEATER AND AIR CONDITIONING 1-97



YES
Open circuit between the No. EB-13
fuse and engine room harness
connector terminal No. 4 (C-24).
NO
YES
• Is there battery voltage between the engine
room harness connector terminal No.3 (C-55)
and ground? Open circuit between the engine room
harness connector terminal No. 2 (C-
55) and the engine room harness
connector terminal No. 1 (C-24).
NO
YES
• Is there continuity between the engine room
harness connector terminal No.1 (C-55) and the
chassis side harness connector terminal No.5
(B-57) ? or (cooler only) the short connector
terminal No.3 (B-79) and the chassis side
harness connector terminal No.5 (B-57)? Open circuit between the No. EB-13
fuse and the engine room harness
connector terminal No. 3 (C-55).
NO
• connect the A/C thermo relay connector.
• Disconnect the electronic thermostat.
• Is there continuity between the engine room
harness connector terminal No. 2 (C-55) and the
engine room harness connector terminal No. 1
(C-24)?
Open circuit between the engine room
harness connector terminal No. 1 (C-
55) or (cooler only) the short
connector No. 3 (B-79) and the
chassis side harness connector
terminal No.5 (B-57). • Is there continuity between the engine room
harness connector (cooler only) terminal No. 4
(C-55) and the chassis side harness connector
terminal No. 11 (B-57)?
YES NO


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ISUZU KB P190 2007