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1B-20 AIR CONDITIONING (OPTIONAL)
A / C CONTROLLER VOLTAGE VALUES TABLE
TerminalWireCircuitMeasurement
groundNormal valueCondition
AC1-1B/WController main
power supplyGround to
engine (Fig. B)10 ± 14 voltsIgnition switch ON with engine
stopped
AC1-2B/YController main
groundGround to body
(Fig. A)± 0.4 ± 0 voltEngine running
AC1 4Or
Refrigerant
p
ressure switchGround to
0 ± 1 volt
Refrigerant pressure within 225 kPa
(2.3 kg / cm
2, 32.7 psi) to 2548 kPa
(26 kg / cm
2, 370 psi) with engine
running
AC1-4Orpressure switch
inputengine (Fig. B)
10 ± 14 volts
Refrigerant pressure below
196 kPa (2.0 kg / cm
2, 28 psi) or
above 3140 kPa (32 kg / cm
2, 455 psi)
with engine running
AC1 7G/B
A / C switch input
and / or defroster
Ground to
8 ± 14 volts
Blower fan motor switch and A / C or
defroster position switch (see NOTE)
ON with engine running
AC1-7G/Bposition switch
input (see NOTE)engine (Fig. B)
0 ± 1.5 volts
Blower fan motor switch or A / C or
defroster position switch (see NOTE)
OFF with engine running
AC1 9Gr/W
Signal input from
ECM (A / C ON
Ground to10 ± 14 voltsApprove of A / C ON
AC1-9Gr/W(
permission
signal)engine (Fig. B)0 ± 1 voltA / C ON forbid
AC1-13Y/B
Signal output to
ECM (A / C ON
request signal)Ground to engine
(Fig. B)0 ± 1.5 volts
Blower fan motor switch and A / C or
defroster position switch (see NOTE)
ON with engine running at evaporator
thermistor temperature input more
than approx. 2.5C (less than 2.5 V
(5840 )) and refrigerant pressure
switch is ON
10 ± 14 voltsExcept the above-mentioned with
engine running
AC1-16P
Compressor
magnet clutch
relay outputGround to engine
(Fig. B)0 ± 1 volt
Blower fan motor switch and A / C or
defroster position switch ON with
engine running at evaporator
thermistor temperature input more
than approx. 2.5C (less than 2.5 V
(5840 )), refrigerant pressure
switch ON and signal input from ECM
ON
10 ± 14 voltsExcept the above-mentioned with
engine running
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AIR CONDITIONING (OPTIONAL) 1B-21
TerminalWireCircuitMeasurement
groundNormal valueCondition
AC2-1L/YSensor groundGround to body
(Fig. A)± 0.4 ± 0 voltEngine running
1.5 volts
(3150 )Evaporator thermistor temperature at
approx. 15C (59F) with engine
running
AC2-2W/B
Evaporator
thermistor
temperature
(evaporator temp.
sensor) input
Ground to engine
(Fig. B)
2.62 volts
(6.311 )
Evaporator thermistor temperature at
approx. 1C (34F) with engine
running
* If the temperature is less than
approx. 1C, in this case
compressor and condenser fan
should be stop (come back at more
than approx. 2.5C (less than
5840 , 2.5 V))
H25
engine
E61-27 /
G16 J20Gr/W
Signal output to
A / C controller
(A / C ON
Ground to engine
(Fig C)
10 ± 14 volts
Required A / C ON (terminal AC-A13)
at engine running with normal
condition (refer to ªINSPECTION OF
ECM AND ITS CIRCUITº in Section
6E)
G16, J20
engines
E61-8
(
permission
signal)(Fig. C)
0 ± 1 volt
Except the above-mentioned with
engine running
In this case compressor should be
stop
H25
engine
E61-28 /
Y/B
Signal input from
A / C controller
Ground to engine
0 ± 1.5 voltsRequire A / C ON
G16, J20
engines
E61-17Y/B(A / C ON request
signal)
g
(Fig. C)
10 ± 14 voltsTurn off the A / C
H25
engine
E61-5 /
G16, J20
engines
E61-22
Y/L
A / C condenser
cooling fan relay
outputGround to engine
(Fig. C)0 ± 1 volt
Blower fan motor switch and A / C or
defroster position switch (see
NOTE) ON with engine running at
evaporator thermistor temperature
input more than approx. 2.5C (less
than 2.5 V (5840 )), refrigerant
pressure switch ON and signal
input from ECM ON
Engine coolant temperature sensor
more than 113C (236F) with
engine running
10 ± 14 voltsExcept the above-mentioned with
engine running
NOTE:
Defroster position switch circuit is equipped with LH vehicle only.
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1. Electric leak detector
AIR CONDITIONING (OPTIONAL) 1B-29
REMOVING MANIFOLD GAUGE SET
When A / C system has been charged with a specified amount of re-
frigerant, remove manifold gauge set as follows:
1) Close low pressure-side valve of manifold gauge set, (The high
pressure-side valve is closed continuously during the process
of charging.).
2) Close refrigerant container valve.
3) Stop engine.
4) Using shop rag, remove charging hoses from service valves.
This operation must be performed rapidly.
WARNING:
High pressure-side is naturally under high pressure.
So, care must be used to protect your eyes and skin.
5) Put caps on service valves.
LEAK-TESTING REFRIGERANT SYSTEM
Whenever a refrigerant leak is suspected in the system or any ser-
vice operation has been performed which may result in disturbing
lines or connections, it is advisable to test for leaks.
Common sense should be used in performing any refrigerant leak
test, since the need and extent of any such test will, in general, de-
pend upon the nature of a complaint and the type of a service per-
formed on the system.
LIQUID LEAK DETECTORS
There are a number of fittings and places throughout the air condi-
tioning system where a liquid leak detector solution may be used
to pinpoint refrigerant leaks.
By merely applying the solution to the area in question with a swab,
bubbles will form within seconds if there is a leak.
For confined areas, such as sections of the evaporator and con-
denser, an electronic (gas) leak detector is more practical for deter-
mining leaks.
WARNING:
To prevent explosions or fires, make sure that there are no
flammables in the vicinity.
When exposed to fire, the refrigerant turns into a poison-
ous gas (phosgene). Do not inhale this gas.
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1. New compressor
2. Removed compressor
3. Excess oil (A ± B)
1B-32 AIR CONDITIONING (OPTIONAL)
REPLENISHING COMPRESSOR OIL
When replacing air conditioning parts with new ones, it is necessary
to replenish oil by the amount supposedly remaining in each part.
When changing gas only
When it is unavoidable to change gas without replacing any compo-
nent part for engine removal and installation or for some other rea-
son, replenish 20 cc oil. When replenishing gas only, oil replenish-
ment it not necessary.
When replacing compressor
Compressor oil is sealed in each new compressor by the amount
required for air conditioner cycle. Therefore, when using a new
compressor for replacement, drain oil from it by the amount calcu-
lated as follows.
ªCº = ªAº ± ªBº
ªCº: Amount of oil to be drained
ªAº: Amount of oil sealed in a new compressor
ªBº: Amount of oil remaining in removed compressor
When replacing other part
Replaced partAmount of compressor oil
to be replenished
Evaporator25 cc
Condenser15 cc
Receiver / dryer20 cc
Hoses10 cc each
Pipes10 cc each
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AIR CONDITIONING (OPTIONAL) 1B-39
COOLING UNIT (EVAPORATOR)
REMOVAL
1) Disconnect negative (±) cable at battery.
2) Disable air bag system. Refer to ªDisabling Air Bag Systemº in
Section 10B.
3) Recover refrigerant by using recovery and recycling equipment.
Be sure to follow the instruction manual for the equipment.
The amount of compressor oil removed must be measured and
the same amount added to the system.
4) For G16 and J20 engine
Disconnect suction pipe (1), and liquid pipe (2) from evaporator
(cooling unit).
CAUTION:
As soon as above hose and pipe are disconnected, cap
opened fittings so that moisture and dust may not enter
cooling unit.
5) Remove blower motor unit. Refer to Section 1A ªHEATER AND
VENTILATIONº.
6) Disconnect thermistor wire coupler.
7) Remove cooling unit (evaporator).
DISASSEMBLY (FOR CAMI PRODUCTION VEHICLE)
1) Remove filter (2) from cooling unit (3) assembly by removing fil-
ter cover (1).
2) Remove screws (1) to separate evaporator upper and lower
cases from each other.
Page 111 of 801
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1
1B-40 AIR CONDITIONING (OPTIONAL)
3) Remove upper case (1) and remove evaporator (2) from lower
case (3).
4) Remove following components from evaporator.
Expansion valve (5)
Thermistor (evaporator temperature sensor) (4)
DISASSEMBLY (FOR IWATA PRODUCTION VEHICLE)
1) Remove filter (2) from cooling unit (3) assembly by removing fil-
ter cover (1).
2) Detach clamps (1) to separate evaporator upper and lower
cases from each other.
3) Remove upper case (1) and remove evaporator (2) from lower
case (3).
4) Remove following components from evaporator.
Expansion valve (5)
Thermistor (evaporator temperature sensor) (4)
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AIR CONDITIONING (OPTIONAL) 1B-41
INSPECTION
1) Check evaporator fins for blockage. If found clogged, use com-
pressed air to clean the fins.
CAUTION:
Do not use water for cleaning of evaporator.
Be careful not to damage evaporator fins. If evaporator
fin is bent, straighten it by using a screwdriver or pair of
pliers. If any leakage is found from fitting or tube, repair
or replace evaporator.
2) Check inlet and outlet fittings for crack or scratch. Repair them
as required.
REASSEMBLY and INSTALLATION
1) Reverse removal and disassembly sequence to install cooling
unit, noting the following points.
Install uniformly the evaporator packing to dash panel hole for
expansion valve.
Adjust fresh air control cable, refer to ªHEATER CONTROL
LEVER ASSEMBLYº in Section 1A.
2) Enable air bag system. Refer to ªEnabling Air Bag Systemº in
Section 10B.
3) Evacuate and charge system. Refer to ªEVACUATINGº and
ªCHARGINGº in this section.
NOTE:
When the thermistor removed, it should be reinstalled in
original position.
If cooling unit or evaporator is replaced, pour 25 cc of refrig-
erating oil to compressor suction-side.
Page 113 of 801
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3. Pipe clamp
1B-42 AIR CONDITIONING (OPTIONAL)
EXPANSION VALVE
INSPECTION
Refer to ªTroubleshooting Procedure Using Manifold Gauge Setº in
this section.
REMOVAL
1) Recover refrigerant by using recovery and recycling equipment.
Be sure to follow the instruction manual for the equipment. The
amount of compressor oil removed must be measured and the
same amount added to the system.
2) Remove front grill.
3) Disconnect suction pipe (1), and liquid pipe (2) from evaporator
(Cooling unit).
CAUTION:
As soon as above hose and pipe are disconnected, cap
opened fittings so that moisture and dust may not enter
cooling unit.
4) Disconnect suction pipe, and liquid pipe from suction hose (1)
and condenser outlet pipe (2).
5) Remove pipe clamp then remove suction pipe and liquid pipe.
6) Remove expansion valve (1).
INSTALLATION
1) Reverse removal sequence to install expansion valve.
2) Evacuate and charge system. Refer to ªEVACUATINGº and
ªCHARGINGº in this section.