Isuzu Amigo / Axiom / Trooper / Rodeo / VehiCross. Manual - part 1082

1A–50 HEATING, VENTILATION AND AIR CONDITIONING (HVAC)

Air Conditioning System

Individual Inspection

Fan Control Knob (Fan Switch) And Air
Conditioning (A/C) Switch

1. Check for continuity between the fan switch and the

A/C switch side connector terminals.

D08RW061

Heater (X-1), Thermostat (X-8), Condenser
Fan (X-11) And Compressor (X-2) Relay

1. Disconnect relays and check for continuity and

resistance between relay terminals.

D

For handling of these relays, refer to Heater Relay
in this section.

825RS179

Pressure Switch

1. Disconnect pressure switch connector and check for

continuity between pressure switch side connector
terminals (1) and (2).

875RY00009

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

HEATING, VENTILATION AND AIR CONDITIONING (HVAC) 1A–51

Condenser Fan

1. Disconnect the condenser fan connector.
2. Connect the battery positive terminal to the

condenser fan side connector terminal No.C-24-1
and negative to the No.C-24-2.

3. Check that condenser fan is rotating correctly.

875RW010

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:

D

Keep your work area clean.

D

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

D

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

D

Beware of discharged refrigerant in enclosed or
improperly ventilated garages.

D

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

D

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

D

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.

D

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

D

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

D

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

D

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.

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.

852RS003

When 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.

1A–52 HEATING, VENTILATION AND AIR CONDITIONING (HVAC)

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.

850RW003

Insert 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–53

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 

Step

Action

Yes

No

1

1. Evacuate the refrigerant system.
2. Charge the refrigerant.

Is there any refrigerant leak?

Repair refrigerant

system.

Go to Step 2.

2

1. 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:

D

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.

D

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.

D

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

D

Pipe connection

D

Sealing section of shaft

D

Mating section or cylinder

Condenser

D

Pipe connection

D

Welds of condenser body

Receiver driver

D

Pipe connection

D

Attaching section of pressure switch

D

Section around the sight glass

Evaporator unit (cooling unit)

D

Pipe connections

D

Connections of expansion valve

D

Brazed sections of evaporator

NOTE:

D

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

D

Pipe connection

D

Caulking section of the hose

D

Hose (cracks, pinholes, flaws)

Pipe

D

Pipe connection

D

Pipe (cracks, flaws)

Charge valve

NOTE:

D

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.

D

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

D

Do not over tighten.

2. Perform a leak test on the refrigerant line fitting.