heating ISUZU AXIOM 2002 Service Owner's Guide

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
1A±29
Condenser Fan Diagnosis
While the air conditioning is ON, the cycling switch in the
triple pressure switch senses the refrigerant pressure,
and activates the condenser fan to improve the cooling
capacity of the condenser when the refrigerant pressure
exceeds a set pressure value. The condenser fan stops
when the air conditioning is turned ªOFFº or when the
pressure goes down below the set pressure value.
D08R200041
ConditionPossible causeCorrection
Condenser fan does not run.±Refer to ªChart Aº.
±Refer to ªChart Bº.

1A±30
HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
Chart ªAº Condenser Fan Does Not Run
StepActionYe sNo
1Are 30A fuse normal?Go to Step 2Replace
2Is relay (X-16) normal?Go to Step 3Replace
3Is pressure switch normal?
Go to Step 4
Switch defective
or insufficient
refrigerant.
4Is fan motor normal?Go to Step 5Replace
51. Disconnect condenser fan relay (X-16).
2. Check to see if battery voltage is present at the chassis side
relay terminal NO. X16-5.
Is there a battery voltage?
Go to Step 6
Repair open
circuit between
Condenser Fan
fuse (30A) and
No.X16-5.
61. Reconnect condenser fan relay (X-16).
2. Check to see if battery voltage is present at chassis side
connector terminal No.C21-3.
Is there a battery voltage?
Go to Step 7
Repair open
circuit between
fuse (10A) and
C21-3.
7Check to see if continuity between chassis side relay terminal
No.X16-2 and the chassis side connector terminal No.C21-4.
Is there a continuity?
Go to Step 8
Repair open
circuit.
8Check to see if continuity between chassis side connector
terminal No. C16-1 and chassis side relay terminal No.X16-1.
Is there a continuity?Poor ground or
open circuit
between chassis
side connector
terminal
No.X16-4 (or
No.C16-2) and
body ground
(No.C10).
Repair open
circuit.
Chart ªBº Condenser Fan Does Not Stop
StepActionYe sNo
11. Disconnect the triple pressure connector.
Does condenser fan stop?
Replace the triple
pressure switch.
Replace the
condenser fan
relay.

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
1A±31
Air Conditioning System
Individual Inspection
Triple Pressure Switch (V6, A/T)
1. Disconnect the connector and check for continuity
between pressure switch side connector terminals (1)
and (2).
2. Reconnect the connector to activate the A/C switch,
and check to see if there is continuity between the
chassis side connector terminals (3) and (4) and the
fan operates.
875RY00010
Condenser Fan
1. Disconnect the condenser fan connector.
2. Connect the battery positive terminal to the
condenser fan side connector terminal No.C-16-1
and negative to the No.C-16-2.
3. Check that condenser fan is rotating correctly.
875R200002
General Repair Procedure
Precautions For Replacement or Repair of
Air Conditioning Parts
There are certain procedures, practices and precautions
that should be followed when servicing air conditioning
systems:

Keep your work area clean.

Always wear safety goggles and protective gloves
when working on refrigerant systems.

Beware of the danger of carbon monoxide fumes
caused by running the engine.

Beware of discharged refrigerant in enclosed or
improperly ventilated garages.

Always disconnect the negative battery cable and
discharge and recover the refrigerant whenever
repairing the air conditioning system.

When discharging and recovering the refrigerant, do
not allow refrigerant to discharge too fast; it will draw
compressor oil out of the system.

Keep moisture and contaminants out of the system.
When disconnecting or removing any lines or parts,
use plugs or caps to close the fittings immediately.
Never remove the caps or plugs until the lines or parts
are reconnected or installed.

When disconnecting or reconnecting the lines, use
two wrenches to support the line fitting, to prevent
from twisting or other damage.

Always install new O-rings whenever a connection is
disassembled.

Before connecting any hoses or lines, apply new
specified compressor oil to the O-rings.

When removing and replacing any parts which
require discharging the refrigerant circuit, the
operations described in this section must be
performed in the following sequence:
1. Use the J-39500 (ACR
4: HFC-134a Refrigerant
Recovery / Recycling / Recharging / System) or
equivalent to thoroughly discharge and recover the
refrigerant.
2. Remove and replace the defective part.
3. After evacuation, charge the air conditioning
system and check for leaks.

1A±32
HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
Repair Of Refrigerant Leaks
Refrigerant Line Connections
Install new O-rings, if required. When disconnecting or
connecting lines, use two wrenches to prevent the
connecting portion from twisting or becoming damaged.
852R200001When connecting the refrigerant line at a block joint,
securely insert the projecting portion of the joint portion
into the connecting hole on the unit side and secure with a
bolt. Apply the specified compressor oil to the O-rings
prior to connecting.
CAUTION: Compressor (PAG) oil to be used varies
according to the compressor model. Be sure to apply
oil specified for the model of compressor.
850RW002
O-rings (2) must be fitted in the groove (1) of refrigerant
line.
850RW003Insert the nut into the union.
First, tighten the nut by hand as much as possible, then
tighten the nut to the specified torque.
850RW004

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
1A±33
Leak Check
Inspection of refrigerant leak
Refrigerant leak may cause an adverse effect not only on
the performance and durability of each component of the
air±conditioner, but also on the global atmosphere.
Therefore, it is most important to repair refrigerant leak
when there is any leak found.
Inspection flow of refrigerant leak
StepActionYe sNo
11. Evacuate the refrigerant system.
2. Charge the refrigerant.
Is there any refrigerant leak?
Repair refrigerant
system.
Go to Step 2
21. Operate the compressor for more than 5 minutes to raise the
pressure on the high pressure side.
Is there any refrigerant leak at high pressure components?
Repair refrigerant
system.
Compressor
operation to be
confirmed.
Inspection Steps
Check the components of air±conditioner to see if there
occurs any refrigerant leak along the flow of refrigerant.
NOTE:

To avoid refrigerant leak detection error, avoid
refrigerant vapor and cigarette smoke presence when
performing the inspection. Also, select a location that
is not susceptible to wind, in case refrigerant vapor is
found it will not be blown off.

Inspection should be conducted chiefly on the pipe
connections and sections where a marked oil
contamination is found. When refrigerant is leaking,
oil inside is also leaking at the same time.

It is possible to visually check the leak from inside the
cooling unit. Follow the method below when
performing the inspection. Remove the drain hose or
resistor of the cooling unit, and insert a leak detector
to see if there are signs of leakage.
High Pressure Side
1. Discharger section of compressor.
2. Inlet/outlet section of condenser.
3. Inlet/outlet section of receiver driver.
4. Inlet section of cooling unit.
Low Pressure Side
1. Outlet section of cooling unit.
2. Intake section of compressor.
Major Checking Points of Refrigerant Leak
Compressor

Pipe connection

Sealing section of shaft

Mating section or cylinder
Condenser

Pipe connection

Welds of condenser bodyReceiver driver

Pipe connection

Attaching section of pressure switch

Section around the sight glass
Evaporator unit (cooling unit)

Pipe connections

Connections of expansion valve

Brazed sections of evaporator
NOTE:

The evaporator and expansion valve are contained in
the case. Remove the drain hose or the resistor of the
cooling unit and insert a leak detector when checking
for any leak.
Flexible hose

Pipe connection

Caulking section of the hose

Hose (cracks, pinholes, flaws)
Pipe

Pipe connection

Pipe (cracks, flaws)
Charge valve
NOTE:

The charge valve, which is used to connect the gauge
manifold, is normally provided with a resin cap. When
the valve inside gets deteriorated, refrigerant will leak
out.Leak at Refrigerant Line Connections
1. Check the torque on the refrigerant line fitting and, if
too loose, tighten to the specified torque.

Use two wrenches to prevent twisting and damage
to the line.

Do not over tighten.
2. Perform a leak test on the refrigerant line fitting.

1A±34
HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
3. If the leak is still present, discharge and recover the
refrigerant from the system.
4. Replace the O-rings.

O-rings cannot be reused. Always replace with new
ones.

Be sure to apply the specified compressor oil to the
new O-rings.
5. Retighten the refrigerant line fitting to the specified
torque.

Use two wrenches to prevent twisting and damage
to the line.
6. Evacuate, charge and retest the system.
Leaks In The Hose
If the compressor inlet or outlet hose is leaking, the entire
hose must be replaced. The refrigerant hose must not be
cut or spliced for repair.
1. Locate the leak.
2. Discharge and recover the refrigerant.
3. Remove the hose assembly.

Cap the open connections at once.
4. Connect the new hose assembly.

Use two wrenches to prevent twisting or damage to
the hose fitting.

Tighten the hose fitting to the specified torque.
5. Evacuate, charge and test the system.
Compressor Leaks
If leaks are located around the compressor shaft seal or
shell, replace or repair the compressor.
Recovery, Recycling, Evacuation and
Charging of HFC-134a
Air conditioning systems contain HFC-134a. This is a
chemical mixture which requires special handling
procedures to avoid personal injury.

Always wear safety goggles and protective gloves.

Always work in a well-ventilated area. Do not weld or
steam clean on or near any vehicle-installed air
conditioning lines or components.

If HFC-134a should come in contact with any part of
the body, flush the exposed area with cold water and
immediately seek medical help.

If it is necessary to transport or carry any container of
HFC-134a in a vehicle, do not carry it in the
passenger compartment.

If it is necessary to fill a small HFC-134a container
from a large one, never fill the container completely.
Space should always be allowed above the liquid for
expansion.

HFC-134a and R-12 should never be mixed as their
compositions are not the same.

HFC-134a PAG oil tends to absorb moisture more
quickly than R-12 mineral oil and, therefore, should
be handled more carefully.

Keep HFC-134a containers stored below 40
C
(104
F).WARNING:

SHOULD HFC-134A CONTACT YOUR EYE(S),
CONSULT A DOCTOR IMMEDIATELY.

DO NOT RUB THE AFFECTED EYE(S). INSTEAD,
SPLASH QUANTITIES OF FRESH COLD WATER
OVER THE AFFECTED AREA TO GRADUALLY
RAISE THE TEMPERATURE OF THE
REFRIGERANT ABOVE THE FREEZING POINT.

OBTAIN PROPER MEDICAL TREATMENT AS
SOON AS POSSIBLE. SHOULD THE HFC-134A
TOUCH THE SKIN, THE INJURY MUST BE
TREATED THE SAME AS SKIN WHICH HAS BEEN
FROSTBITTEN OR FROZEN.
Refrigerant Recovery
The refrigerant must be discharged and recovered by
using the J-39500 (ACR4:HFC-134a Refrigerant
Recovery/Recycling/Recharging/System) or equivalent
before removing or mounting air conditioning parts.
1. Connect the high and low charging hoses of the
ACR
4(or equivalent) as shown below.
901R100022
Legend
(1) Low Side
(2) High Side
2. Recover the refrigerant by following the
Manufacturer's Instructions.
3. When a part is removed, put a cap or a plug on the
connecting portion so that dust, dirt or moisture
cannot get into it.

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
1A±35
Refrigerant Recycling
Recycle the refrigerant recovered by J-39500
(ACR4:HFC-134a Refrigerant Recovery / Recycling /
Recharging / System) or equivalent.
For the details of the actual operation, follow the steps in
the ACR
4(or equivalent) Manufacturer's Instructions.
Evacuation of The Refrigerant System
901R100023
Legend
(1) Low Side
(2) High Side
NOTE: Explained below is a method using a vacuum
pump. Refer to the ACR4(or equivalent) manufacturer's
instructions when evacuating the system with a ACR4(or
equivalent).
Air and moisture in the refrigerant will cause problems in
the air conditioning system. Therefore, before charging
the refrigerant, be sure to evacuate air and moisture thor-
oughly from the system.
1. Connect the gauge manifold.

High-pressure valve (HI) Ð Discharge-side.

Low-pressure valve (LOW) Ð Suction-side.
2. Discharge and recover the refrigerant.
3. Connect the center hose of the gauge manifold set to
the vacuum pump inlet.
4. Operate the vacuum pump, open shutoff valve and
then open both hand valves.
5. When the low-pressure gauge indicates
approximately 750 mmHg (30 inHg), continue the
evacuation for 5 minutes or more.
6. Close both hand valves and stop the vacuum pump.
7. Check to ensure that the pressure does not change
after 10 minutes or more.

If the pressure changes, check the system for
leaks.

If leaks occur, retighten the refrigerant line
connections and repeat the evacuation steps.8. If no leaks are found, again operate the vacuum pump
for 20 minutes or more. After confirming that the
gauge manifold pressure is at 750 mmHg (30 inHg),
close both hand valves.
9. Close positive shutoff valve. Stop the vacuum pump
and disconnect the center hose from the vacuum
pump.
Charging The Refrigerant System
There are various methods of charging refrigerant into the
air conditioning system.
These include using J-39500 (ACR
4:HFC-134a
Refrigerant Recovery/Recycling/Recharging/System) or
equivalent and direct charging with a weight scale
charging station.
Charging Procedure

ACR
4(or equivalent) Method
For the charging of refrigerant recovered by ACR4(or
equivalent), follow the manufacturer's instruction.
901R100022
Legend
(1) Low Side
(2) High Side

Direct charging with a weight scale charging
station method
1. Make sure the evacuation process is correctly
completed.
2. Connect the center hose of the manifold gauge to the
weight scale.

1A±36
HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
3. Connect the low pressure charging hose of the
manifold gauge to the low pressure side service valve
of the vehicle.
4. Connect the high pressure charging hose of the
manifold gauge to the high pressure side service
valve of the vehicle.
901R100021
Legend
(1) Low Side
(2) High Side
(3) Refrigerant Container
(4) Weight Scale
5. Place the refrigerant container(3) up right on a weight
scale(4).
Note the total weight before charging the refrigerant.
a. Open the refrigerant container valve.
b. Open the low side vale on the manifold gauge set.
Refer to the manufacturer's instructions for a
weight scale charging station.
901RS144
6. Perform a system leak test:

Charge the system with approximately 200 g
(0.44 lbs) of HFC-134a.

Make sure the high pressure valve of the manifold
gauge is closed.

Check to ensure that the degree of pressure does
not change.

Check for refrigerant leaks by using a HFC-134a
leak detector.

If a leak occurs, recover the refrigerant. Repair the
leak and start all over again from the first step of
evacuation.
7. If no leaks are found, continue charging refrigerant to
the air conditioning system.

Charge the refrigerant until the scale reading
decreases by the amount of the charge specified.
Specified amount: 700 g (1.54 lbs)

If charging the system becomes difficult:
1. Run the engine at idle and close all the vehicle
doors.
2. Turn A/C switch ªONº.
3. Set the fan switch to its highest position.
4. Set the air source selector lever to ªCIRCº.
5. Slowly open the low side valve on the manifold
gauge set.
WARNING: BE ABSOLUTELY SURE NOT TO OPEN
THE HIGH PRESSURE VALVE OF THE MANIFOLD
GAUGE. SHOULD THE HIGH PRESSURE VALVE BE
OPENED, THE HIGH PRESSURE REFRIGERANT
WOULD FLOW BACKWARD, AND THIS MAY CAUSE
THE REFRIGERANT CONTAINER TO BURST.

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
1A±37
8. When finished with the refrigerant charging, close the
low pressure valve of the manifold gauge and
container valve.
9. Check for refrigerant leaks.
Checking The A/C System
1. Run the engine and close all the vehicle doors.
2. Turn A/C switch ªONº, set the fan switch to its highest
position.
3. Set the air source switch to ªCIRCº, set the
temperature switch to the full cool position.
4. Check the high and low pressure of the manifold
gauge.

Immediately after charging refrigerant, both high
and low pressures might be slightly high, but they
settle down to the pressure guidelines shown
below:

The ambient temperature should be between
25±30
C (77±86
F).

The pressure guideline for the high-pressure side is
approximately 1372.9±1863.3 kPa (199.1±270.2
psi).

The pressure guideline for the low-pressure side is
approximately 147.1±294.2 kPa (21.3±42.7 psi).

If an abnormal pressure is found, refer to
Checking
The Refrigerant System With Manifold Gauge in
this section.
5. Put your hand in front of the air outlet and move the
temperature switch of the control panel to different
positions. Check if the outlet temperature changes as
selected by the control switch.

1A±38
HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
Compressor Assembly
Compressor Assembly and Associated Parts (6VE1)
852R100002
Legend
(1) Compressor Bracket
(2) Magnetic Clutch Harness Connector
(3) Compressor
(4) O-ring(5) To Evaporator
(6) Suction Line (Low-Pressure Hose)
(7) Discharge Line (High-Pressure Hose)
(8) To Condenser
(9) Serpentine Belt
Removal
1. Disconnect the battery ground cable.
2. Discharge and recover refrigerant

Refer to
Refrigerant Recovery in this section.
3. Disconnect magnetic clutch harness connector.