Page 1417 of 1449
HEATER, AIR CONDITIONER AND VENTILATION–On-vehicle Service55-15
COMPRESSOR DRIVE BELT ADJUSTMENT
Refer to GROUP 11 - On-vehicle Service.
DUAL PRESSURE SWITCH CHECK
1. Remove the dual pressure switch connector and connect
the high/low pressure side terminals located on the
harness side as shown in the illustration.
2. Install a gauge manifold to the high
-pressure side service
valve of the refrigerant line. (Refer to 55-42.)
3. When the high/low pressure sides of the dual pressure
switch are at operation pressure (ON) and there is
continuity between the respective terminals, then the
condition is normal. If there is no continuity, replace the
switch.
Dual pressure switch
ON
OFF
19620
kPa
2202023523722940176
Hood support rod
Page 1418 of 1449

HEATER, AIR CONDITIONER AND VENTILATION–On-vehicle Service55-16
CHARGING
1. With the handles turned back all the way (valve closed),
install the adaptor valve to the low-pressure side of the
gauge manifold.
2. Connect the charging hose (blue) to the adaptor valve.
3. Connect the quick joint (for low
-pressure) to the charging
hose (blue).
4. Connect the quick joint (for low
-pressure) to the low-
pressure service valve.
NOTE
The low-pressure service valve should be connected to
the suction hose.
Caution
(1) Use tools that are suited to R134a.
(2) To install the quick joint, press section “A” firmly
against the service valve until a click is heard.
When connecting, run your hand along the hose
while pressing to ensure that there are no bends
in the hose.
5. Close the high and low
-pressure valves of the gauge
manifold.
6. Install the vacuum pump adaptor to the vacuum pump.
7. Connect the vacuum pump plug to the vacuum pump
adaptor.
8. Connect the charging hose (yellow) to the R-134a
connection port of the vacuum pump adaptor.
9. Tighten the adaptor valve handle (valve open).
10. Open the low
-pressure valve of the gauge manifold.
11. Turn the power switch of the vacuum pump to the ON
position.
NOTE
Even if the vacuum pump power switch is turned ON,
the vacuum pump will not operate because of the power
supply connection in step (7).
Low-pressure
valveHigh-pressure
valve
Gauge manifold
Adapter
valveCharging hose
(yellow)
Charging hose
(blue)
R-12
connection
portSwitch
R-134a
connection
port
Vacuum
pump
adaptor
Vacuum
pump
Power supply
plug
Switch Quick
joint (for
low pres-
sure)
Low-pressure
service valve
SleeveA
Page 1419 of 1449

HEATER, AIR CONDITIONER AND VENTILATION–On-vehicle Service55-17
12. Turn the vacuum pump adaptor switch to the R134a side
to start the vacuum pump.
Caution
Do not operate the compressor for evacuation.
13. Evacuate to a vacuum reading of 100 kPa or higher (takes
approx. 10 minutes).
14. Turn the vacuum pump adaptor switch OFF and allow
to stand it for 5 minutes.
Caution
Do not operate the compressor in the vacuum
condition; damage may occur.
15. Carry out a leak test. (Good if the negative pressure
does not drop.)
Caution
If the negative pressure drops, increase the tightness
of the connections, and then repeat the evacuation
procedure from step (12).
16. With the handle turned back all the way (valve open),
install the charging valve to the service can.
17. Turn the handle of the adaptor valve back all the way
(valve closed), remove it from the gauge manifold and
install the service can.
18. Tighten the handle of the charging valve (valve closed)
to puncture the service can.
19. Turn the handle of the charging valve back (valve open)
and tighten the handle of the adaptor valve (valve open) to
charge the system with refrigerant.
Caution
If the service can is inverted, liquid refrigerant may
be drawn into the compressor damaging it by liquid
compression. Keep the service can upright to ensure
that refrigerant is charged in gas state.
20. If the refrigerant is not drawn in, turn the handle of the
adaptor valve back all the way (valve closed).
21. Check for gas leaks using a leak detector.
If a gas leak is detected, re-tighten the connections, and
then repeat the charging procedure from evacuation in
step (12).
Caution
The leak detector for R-134a should be used.
22. Start the engine.
23. Operate the A/C and set to the lowest temperature (MAX.
COOL).
Low-pressure
service valveVacuum pump
Adaptor valveValve open
Valve close
Charging
valve
Service can
Charging valve
Service can
(Refrigerant container)
Low-pressure
service valve
Page 1420 of 1449

HEATER, AIR CONDITIONER AND VENTILATION–On-vehicle Service55-18
24. Fix the engine speed at 1,500 r/min.
25. Tighten the handle of the adaptor valve (valve open)
to charge the required volume of refrigerant.
Caution
If the service can is inverted, liquid refrigerant may
be drawn into the compressor damaging it by liquid
compression. Keep the service can upright to ensure
that refrigerant is charged in gas state.
26. After charging with refrigerant, turn the handle of the
adaptor valve back all the way (valve closed).
27. Tighten the charging valve handle (valve closed).
Remove the quick joint (for low-pressure) from the
low-pressure service valve.
NOTE
If the service can is not emptied completely, keep the
handles of the charging valve and adaptor valve closed
for the next charging.
CORRECTING LOW REFRIGERANT LEVEL IN
CASE THE SERVICE CAN IN USED
1. Install the charge valve with the handle turned all the
way back (valve open) to the service can.
2. Install the adaptor valve with the handle turned all the
way back (valve close) to the charging valve.
3. Connect the charging hose (blue) to the adaptor valve.
4. Connect the charging hose (blue) to the quick joint (for
low-pressure).
5. Tighten the handle of the charge valve (valve close),
and pierce the service can.
6. Turn the handle of the adaptor valve to bleed the air.
7. Install the quick joint (for low-pressure) to the low-pressure
service valve.
NOTE
The low-pressure service valve should be connected to
the suction hose.
Valve open
Valve close
Service can
(Refrigerant
container)Charge valve
Adaptor valve
Charging hose (blue)
Quick joint (for low-pressure)
Quick joint
(for low-pressure)
Low-pressure
service valve
Page 1421 of 1449

HEATER, AIR CONDITIONER AND VENTILATION–On-vehicle Service HEATER, AIR CONDITIONER AND VENTILATION–On-vehicle Service55-19
8. Start the engine.
9. Operate the air conditioner and set at the lowest
temperature (MAX. COOL).
10. Fix the engine speed at 1,500 r/min.
11. Tighten the handle of the adaptor valve (valve open),
and replenish refrigerant while checking the quantity
through the sight glass.
Caution
If the service can is inverted, liquid refrigerant may
be draw into the compressor damaging it by liquid
compression. Keep the service can upright to ensure
that refrigerant is changed in gas state.
12. After replenishing is completed, turn the handle of the
adaptor valve all the way back (valve close), and remove
the quick joint.
NOTE
When there is remainder of refrigerant in the service can,
keep it for next use with the charge value and the valve
of the adaptor valve being closed.
DISCHARGING SYSTEM
Use the refrigerant recovery unit to discharge refrigerant gas
from the system.
NOTE : Refer to the Refrigerant Recovery and Recycling
Unit Instruction Manual for operation of the unit.
REFILLING OF OIL IN THE A/C SYSTEM
Too little oil will provide inadequate compressor lubrication
and cause a compressor failure. Too much oil will increase
discharge air temperature.
When a compressor is installed at the factory, it contains
130 cm
3of refrigerant oil. While the A/C system is in operation,
the oil is carried through the entire system by the refrigerant.
Some of this oil will be trapped and retained in various parts
of the system.
When the following system components are changed, it is
necessary to add oil to the system to replace the oil being
removed with the component.
Compressor oil: SUN PAG 56
Quantity
Condenser: 180 cm
3
Charging valve
Service can
(Refrigerant container)
Low-pressure
service valve
Page 1422 of 1449

HEATER, AIR CONDITIONER AND VENTILATION–On-vehicle Service HEATER, AIR CONDITIONER AND VENTILATION–On-vehicle Service55-20
PERFORMANCE TEST
1. The vehicles to be tested should be in a place that is
not in direct sunlight.
2. Close the high and low-pressure valve of the gauge
manifold.
3. Connect the charging hose (blue) to the low-pressure
valve and connect the charging hose (red) to the
high-pressure valve of the gauge manifold.
4. Install the quick joint (for low-pressure) to the charging
hose (blue), and connect the quick joint (for high-pressure)
to the charging hose (red).
5. Connect the quick joint (for low-pressure) to the
low-pressure service valve and connect the quick joint
(for high-pressure) to the high-pressure service valve.
NOTE
The high-pressure service valve is on liquid pipe A and the
low-pressure service valve is on the suction hose.
Caution
To connect the quick joint, press section “A” firmly
against the service valve until a click is heard.
When connecting, run your hand along the hose while
pressing to ensure that there are no bends in the
hose.
6. Start the engine.
7. Set the controls to the A/C as follows:
DA/C switch: A/C - ON position
DMode selection: Face position
DTemperature control: Max. cooling position
DAir selection: Recirculation position
DBlower switch: HI (Fast) position
8. Keep engine speed to idling speed with A/C clutch engaged.
9. Engine should be warmed up with doors and all windows
opened.
10. Insert a thermometer in the center A/C outlet and operate
the engine for 20 minutes.
11. Note the discharge air temperature.
NOTE
If the clutch cycles, take the reading before the clutch
disengages.
Performance Temperature Chart
Garage ambient temperature_C20253035
Discharge air temperature_C8-1112 - 1617 - 2122.5 - 27.5
Compressor high-pressure kPa740 - 840950 - 1,0501,160 - 1,3001,360 - 1,550
Compressor low-pressure kPa150 - 190190 - 240240 - 300300 - 375
Low-pressure valve
High-pressure valve
Gauge manifold
Charging
hose (red)
Charging
hose (blue)
Adaptor
valve (for low
pressure)Sleeve
Adaptor valve
(for high pressure)
Low-
pressure
service
valveHigh-
pressure
service
valveA
Thermometer
Page 1423 of 1449

HEATER, AIR CONDITIONER AND VENTILATION–On-vehicle Service55-21
REFRIGERANT LEAK REPAIR
LOST CHARGE
If the system has lost all charge due to a leak:
1. Evacuate the system. (See procedure.)
2. Charge the system with approximately one
pound of refrigerant.
3. Check for leaks.
4. Discharge the system.
5. Repair leaks.
6. Replace receiver drier.
Caution
Replacement filter-drier units must be
sealed while in storage. The drier used in
these units will saturate water quickly upon
exposure to the atmosphere. When
installing a drier, have all tools and supplies
ready for quick reassembly to avoid keeping
the system open any longer than necessary.
7. Evacuate and charge system.
LOW CHARGE
If the system has not lost all of its refrigerant charge;
locate and repair all leaks. If it is necessary to
increase the system pressure to find the leak
(because of an especially low charge) add
refrigerant. If it is possible to repair the leak without
discharging the refrigerant system, use the
procedure for correcting low refrigerant level.HANDLING TUBING AND FITTINGS
Kinks in the refrigerant tubing or sharp bends in
the refrigerant hose lines will greatly reduce the
capacity of the entire system. High pressures are
produced in the system when it is operating.
Extreme care must be exercised to make sure that
all connections are pressure tight. Dirt and moisture
can enter the system when it is opened for repair
or replacement of lines or components. The
following precautions must be observed. The
system must be completely discharged before
opening any fitting of connection in the refrigeration
system. Open fittings with caution even after the
system has been discharged. If any pressure is
noticed as a fitting is loosened, allow trapped
pressure to bleed off very slowly.
Never attempt to rebend formed lines to fit. Use
the correct line for the installation you are servicing.
A good rule for the flexible hose lines is keep the
radius of all bends at least 10 times the diameter
of the hose.
Sharper bends will reduce the flow of refrigerant.
The flexible hose lines should be routed so that
they are at least 80 mm from the exhaust manifold.
It is good practice to inspect all flexible hose lines
at least once a year to make sure they are in good
condition and properly routed.
Unified plumbing connections with O-rings, these
O-rings are not reusable.
COMPRESSOR NOISE
You must first know the conditions when the noise
occurs. These conditions are: weather, vehicle
speed, in gear or neutral, engine temperature or
any other special conditions.
Noises that develop during A/C operation can often
be misleading. For example: what sounds like a
failed front bearing or connecting rod, may be
caused by loose bolts, nuts, mounting brackets,
or a loose clutch assembly. Verify accessory drive
belt tension (power steering or alternator).
Improper accessory drive belt tension can cause
a misleading noise when the compressor is
engaged and little or no noise when the compressor
is disengaged.
Drive belts are speed-sensitive. That is, at different
engine speeds, and depending upon belt tension,
belts can develop unusual noises that are often
mistaken for mechanical problems within the
compressor.ADJUSTMENT
1. Select a quiet area for testing. Duplicate
conditions as much as possible. Switch
compressor on and off several times to clearly
identify compressor noise. To duplicate high
ambient conditions (high head pressure),
restrict air flow through condenser. Install
manifold gauge set to make sure discharge
pressure doesn’t exceed 2,070 kPa.
2. Tighten all compressor mounting bolts, clutch
mounting bolt, and compressor drive belt.
Check to assure clutch coil is tight (no rotation
or wobble).
3. Check refrigerant hoses for rubbing or
interference that can cause unusual noises.
4. Check refrigerant charge. (See “Charging
System”.)
5. Recheck compressor noise as in Step 1.
6. If noise still exists, loosen compressor mounting
bolts and retorque. Repeat Step 1.
7. If noise continues, replace compressor and
repeat Step 1.
Page 1424 of 1449
HEATER, AIR CONDITIONER AND VENTILATION–On-vehicle Service55-22
BLOWER RELAY CONTINUITY CHECK
System voltageTerminal No.yg
1345
When current is
not supplied
When current is
supplied
A/C COMPRESSOR RELAY CONTINUITY CHECK
System voltageTerminal No.yg
3214
When current is
not supplied
When current is
supplied
Blower fan relay
Blower relay
A/C compressor relay