heater ISUZU AXIOM 2002 Service User Guide

1A±10
HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
10. Pull out the door lever while raising up the catch of the
door lever.
11. Remove clip.
Installation
To install, follow the remove steps in the reverse order,
noting the following points:
1. Apply grease to the mode sub-lever and to the
abrasive surface of the heater unit.
2. After installing the link unit, check to see if the link unit
operates correctly.

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
1A±11
Heater Temperature Control Link Unit
Disassembled View
860R200003
Legend
(1) Case (Temperature control)
(2) Door Lever
(3) Clip
(4) Rod(5) Clip
(6) Sub-lever
(7) Mix Actuator
(8) Heater Unit
Removal
1. Disconnect the battery ground cable.
2. Drain engine coolant.
3. Discharge and recover refrigerant (with air
conditioning).

Refer to
Refrigerant Recovery in this section.
4. Remove heater unit.

Refer to
Heater Unit in this section.
5. Remove mix actuator.
6. Remove the case (Temperature control) from the
heater unit.
7. Remove rod.
8. Remove sub-lever.
9. Pull out the door lever while raising up the catch of the
door lever.
10. Remove clip.
Installation
To install, follow the removal steps in the reverse order,
noting the following points:
1. Apply grease to the sub-lever and to the abrasive
surface of the heater unit.
2. After installing the link unit, check to see if the link unit
operates correctly.

1A±12
HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
Blower Assembly
Blower Assembly and Associated Parts
873R200004
Legend
(1) Instrument Panel Assembly
(2) Blower Assembly(3) Evaporator Assembly
(4) Heater Unit
Removal
1. Disconnect the battery ground cable.
2. Discharge and recover refrigerant (with air
conditioning).

Refer to
Refrigerant Recovery in this section.
3. Remove instrument panel assembly.

Refer to
Instrument Panel Assembly in Body and
Accessories section.
4. Disconnect power transistor connector.
5. Remove evaporator assembly.

Refer to
Evaporator Assembly in this section.
6. Disconnect blower motor/intake actuator connector.
7. Remove blower assembly.
Installation
To install, follow the removal steps in the reverse order.

1A±16
HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
Rear Heater Duct, Defroster Nozzle and Ventilation Duct
Rear Heater Duct, Defroster Nozzle, Ventilation Duct and Associated Parts
840R200009
Legend
(1) Defroster Nozzle
(2) Cross Beam Assembly
(3) Center Ventilation Duct and Side Defroster
Duct(4) Instrument Panel Bracket W/Suspension
Control Unit
(5) Instrument Panel Assembly
(6) Rear Heater Duct
(7) Ventilation Lower Duct
Removal
1. Disconnect the battery ground cable.
2. Remove instrument panel assembly.

Refer to
Instrument Panel Assembly in Body and
Accessories section.
3. Remove center ventilation duct and side defroster
duct.

Remove 5 screws.4. Remove instrument panel brackets w/suspension
control unit.

Refer to
Cross Beam Assembly in Body and
Accessories section.
5. Remove cross beam assembly.

Refer to
Cross Beam Assembly in Body and
Accessories section.
6. Remove ventilation lower duct.

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
1A±17
7. Remove rear heater duct.

Remove foot rest carpet and 3 clips.
8. Remove defroster nozzle.
Installation
To install, follow the removal steps in the reverse order,
noting the following point:
1. Connect each duct and nozzle securely leaving no
clearance between them and making no improper
matching.

1A±18
HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
Air Conditioning System
General Description
Air Conditioning Refrigerant Cycle Construction
C01RY00013
Legend
(1) Duct Sensor
(2) Evaporator Core
(3) Evaporator Assembly
(4) Temperature Sensor
(5) Blower Motor
(6) Expansion Valve
(7) Pressure Switch
(8) Receiver/Drier(9) Condenser
(10) Compressor
(11) Magnetic Clutch
(12) Mode (HEAT) Control Door
(13) Temp. Control Door (Air Mix Door)
(14) Heater Core
(15) Mode (VENT) Control Door
(16) Heater Unit
(17) Mode (DEF) Control Door
The refrigeration cycle includes the following four
processes as the refrigerant changes repeatedly from
liquid to gas and back to liquid while circulating.

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
1A±51
Main Data And Specifications
General Specifications
Heater Unit
Temperature controlReheat air mix system
Capacity4.3 kw (3700 Kcal./hr.)
Air flow280 m
/h
HEATER CORE
TypePlate and corrugate fin
Element dimension167 mm (6.6 in.) y 151 mm (5.9 in.) y 35 mm (1.4 in.)
Radiating areaApprox. 2.4 m
EVAPORATOR ASSEMBLY
Capacity4.8 kw (4100 Kcal./hr.)
Air flow430 m
/hr
EVAPORATOR CORE
TypeAl-laminate louver fin type
Element dimension235 mm (9.3 in.) y 224 mm (8.8 in.) y 60 mm (2.4 in.)
EXPANSION VALVE
TypeInternal pressure equalizer type
CONDENSER
TypeParallel flow type
Radiation performance14.8 kw (12,700 Kcal./hr.)
CONDENSER FAN
Air flow850 m3/h
Fan size
261
RECEIVER/DRIER
TypeAssembly includes triple pressure switch
Internal volume300 cc (10 fl.oz.)
PRESSURE SWITCH
TypeTriple pressure switch
Low pressure control
ON: 206.0+30.0 kPa (29.8+4.3 psi)
OFF: 176.5+19.6 kPa (25.6+2.8 psi)
Medium pressure control
ON: 1471.0+98.1 kPa (213.3+14.2 psi)
OFF: 1078.7+117.7 kPa (156.4+17.7 psi)
High pressure control
ON: 2353.6+196.1 kPa (341.3+28.4 psi)
OFF: 2942.0+196.1 kPa (426.6+28.4 psi)
REFRIGERANT
TypeHFC-134a
Specified amount700 g (1.54 lbs.)

1A±64
HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
Automatic Air Conditioning System
General Description
Using a variety of sensors, this automatic air conditioner
accurately senses outside air temperature, solar
radiation quantity, evaporator's blowing temperature, and
interior temperature, then enters these data to the
automatic air conditioner control unit (equipped with the
built-in micro-computer). The data provided to the control
unit enables to automatically control blow temperatureand blow air quantity, turn on or off the compressor and
switch the blow port as well as switching between the
fresh air intake and interior air circulation.
Resetting the automatic function allows you to switch to
the manual control mode.
The self-diagnoisis function of the automatic air
conditioner control unit (with the built-in micro-computer)
allows the unit to access and diagnose a failed part easier
and quicker.
Automatic Air Conditioner Parts Configuration
865R200050
Legend
(1) In Car Sensor
(2) Sun Sensor
(3) Ambient Sensor
(4) Intake Actuator
(5) Blower Unit
(6) Max ± High Relay
(7) Display(8) Audio & Switch Assembly
(9) Evaporator Assembly
(10) Duct Sensor
(11) Mix Actuator
(12) Heater Unit
(13) Automatic Air Conditioner Control Unit
(14) Mode Actuator

1A±70
HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
Functions and Features
Automatic air conditioning control unit
The control unit features a prominent control and display
panel that clearly shows air conditioner operational
settings (delivered air volume, air outlet location,
inside/outside air circulation, and set temperature).
Desired temperature can be set in ±17
C (1
F)
increments. The current setting appears on the digital
display.
Automatic temperature control
Vehicle interior temperature is maintained at the set level.
It is unaffected by changes in vehicle speed, outside air
temperature, and number of passengers.
Maximum cooling and heating
Moving the switch to the 18
C (65
F) position provides
maximum cooling. Moving the switch to the 32
C (90
F)
position provides maximum heating.
Automatic air flow control
Air flow is automatically and precisely regulated in
response to set temperature change and/or changes in
heater unit mixing door aperture.
Automatic air outlet selection
Appropriate air outlets (VENT, BE-LEVEL, FOOT, or
DEF) are selected in response to changes in outlet
temperatures. The mode switch permits manual selection
of the desired air outlet.
Air source (Fresh air intake from outside the
vehicle or recirculation of the air inside the vehicle)
selection
Automatic switching between outside air (FRESH),
recirculated inside air (RECIRC), or a combination of the
two (MIX) occurs in response to changes in outlet
temperatures.The intake switch permits manual
selection of the air source (FRESH or RECIRC). Mixing
of the two sources is not possible during manual
operation. When the defrost mode switch (DEF) is
pressed, the system automatically switches to outside air
intake.
Cooler start-up control
When the vehicle is parked in a hot area for an extended
period of time, the evaporator becomes hot. When the
cooler is turned on, hot air is blown into the vehicle until
the evaporator cools down. The cooler start-up control
prevents blower operation until the evaporator is able to
provide cool air.
Heater start-up control
When the vehicle is parked in a cold area for an extended
period of time, the heater core becomes cold. When the
heater is turned on, cold air is blown into the vehicle until
the heater core heats up. The heater start-up control
prevents blower operation to the air outlets until the
heater core is able to provide warm air. Air is delivered
through the defrost outlets.
Solar radiation offset
The sun sensor uses a photodiode to precisely determine
the amount of solar radiation affecting the vehicle. The
cooler operates in response to this radiation to quickly
correct the vehicle interior temperature.Switch position memory
Current switch positions are stored in memory when the
ignition switch is turned off. When the ignition switch is
turned on again, the switches automatically return to the
position they were in when the ignition switch was turned
off. This simplifies the restarting procedure.
Self-diagnosis function
The self-diagnosis switches on the control panel permit
easy system troubleshooting. Refer to ªSelf-Diagnosisº
later in this Section.

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
1A±73
Air Control Functions
C01R200013
Legend
(1) DEF Door
(2) Air Mix Door
(3) Evaporator Core
(4) Fresh Air Intake
(5) Interior Air Intake
(6) Blower Unit(7) Evaporator Unit
(8) Heater Core
(9) Heater Unit
(10) Sub Air Mix Door
(11) FOOT Door
(12) VENT Door