Page 843 of 1500

ON-VEHICLE SERVICE
HEATER, AIR CONDITIONING AND VENTILATION55-142
4. At this time, check to see that the voltage of A/C pressure
sensor terminal No. 2 reflects the specifications of the fig-
ure.
NOTE: The allowance shall be defined as
5%.
COMPRESSOR DRIVE BELT ADJUSTMENTM1552001000357
Refer to GROUP 00, Maintenance Service Drive Belts
P.00-39.
CHARGING M1552001200403
Use the refrigerant recovery station to charge the refrigerant.
METHOD BY USING REFRIGERANT RECOVERY
AND RECYCLING UNIT
Using the refrigerant recovery and recycling unit, refill the
refrigerant.
NOTE: Refer to the Refrigerant Recovery and Recycling Unit’s
Instruction Manual for operation of the unit.
DISCHARGING SYSTEM
Use the refrigerant recovery unit to discharge refrigerant gas
from the system.
NOTE: Refer to the Refrigerant Recovery and Recycling Unit’s
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 dis-
charge air temperature.
When a compressor is installed at the factory, it contains 140
ml of 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 sys-
tem.
When the following system components are changed, it is nec-
essary to add oil to the system to replace the oil being removed
with the component.
Compressor oil: ND Oil 8
Quantity:
Evaporator: 40 ml
Condenser: 40 ml
Page 848 of 1500

ON-VEHICLE SERVICE
HEATER, AIR CONDITIONING AND VENTILATION55-147
TEST PROCEDURES
1. Select a quiet area for testing.
2. Duplicate problem (customer complaint) as much as
possible.
3. Judge if the noise is abnormal (ie. it is important to
understand the characteristics of the vehicle and its normal
state to judge what is abnormal) - Compare with similar
vehicle if necessary.
4. Detail what and how noise occurs.
5. Find the noise source and verify its transmission by isolating
the subject part from the vehicle.
6. Repair the problem.
7. Explain and report your findings.
DETAILS OF A/C NOISE
POSSIBLE CAUSES, CHECKS AND REPAIRS
NOISE DESCRIPTION WHEN IT OCCURS SOURCE OF NOISE
Rumbling (Bearing noise) With A/C On or Off Magnetic clutch, idler pulley
Clang-Clack noise When compressor is engaged Magnetic clutch operation
Squawking (Belt sliding noise) When compressor is engaged V-belt
Whistling or Whooping noise Immediately after the A/C is
engaged.Expansion valve
Hissing or swishing noise When A/C is engaged, but
decreases as flow is stable Refrigerant flow
Rattling (Internal compressor) When compressor is operating Compressor internal part
Wooing (Resonant noise) With A/C On, occurs at certain
speed.Resonance of accessories
Cooing (Discharge pulsation
noise)With A/C On or Off Resonating noise with the vehicle
body
NOISE DESCRIPTION POSSIBLE CAUSE CHECK REPAIR
Rumbling (Bearing
noise)Bearing damage in rotor Manual rotation of bearing Replace compressor
Rotor slipping on boss Wear on compressor boss
surfaceReplace compressor
Bearing damage in pulley Check alignment between
pulleysReplace compressor
Clang-Clack noise Hub to stator misaligned Wear on inner clutch face Replace compressor
Gap between clutch
surface is too largeCheck Air gap is within
specificationReplace compressor
Squawking (Belt sliding
noise)Oil/water between the belt
and rotor surfaceOil and water
contaminationClean
Low belt tension Belt tension Reset or Replace belt and
set tension to correct
specification
Whistling or Whooping
noiseVibration of expansion
valveExpansion valve Replace TX valve
Page 849 of 1500

ON-VEHICLE SERVICE
HEATER, AIR CONDITIONING AND VENTILATION55-148
POWER RELAY CHECKM1552008800321
BLOWER RELAY CONTINUITY CHECK
Hissing or swishing
noiseLow refrigerant quantity Refrigerant level Check system for leaks
and charge to
specification
Rattling (Internal
compressor)Lack of lubricating oil. In a
system with a gas leak
the oil has escaped with
the refrigerantRattling noise from
internal compressorRepalce the compressor
and also fix the system
leak to prevent
reoccurrance
Wooing (Resonant
noise)Drive accessory (P/S
pump, Alternator,etc)
resonating at specific
engine speedThe drive accessories for
vibrationStop vibrations of the
assembly or modify
transmission route to the
vehicle body
Cooing (Discharge
pulsation noise)Pressure fluctuation of
refrigerant discharged
from compressor, which
vibrates the high pressure
pipingRemove the piping
mounting clamps and
re-check. Hold the
condenser without
mountings by hand and
re-checkPut rubber bush between
pipe clamps and the
vehicle body. decrease
refrigerant to minimum
specified level. NOISE DESCRIPTION POSSIBLE CAUSE CHECK REPAIR
BATTERY
VOLTAGETESTER
CONNECTIONSPECIFIED
CONDITION
Not applied 4
5 Open circuit
Connect
terminal 1 to the
positive battery
terminal
Connect
terminal 3 to the
negative battery
terminal4
5 Less than 2 ohms
Page 853 of 1500
Page 866 of 1500

COMPRESSOR ASSEMBLY AND DRIVE BELT
HEATER, AIR CONDITIONING AND VENTILATION55-165
REMOVAL SERVICE POINTS
.
<> FLEXIBLE SUCTION HOSE AND FLEXIBLE
DISCHARGE HOSE DISCONNECTION
As the compressor oil and receiver are highly moisture
absorbent, use a non-porous material to plug the hose and
nipples.
To prevent the entry of dust or other foreign bodies, plug the
dismantled hoses and compressor nipples.
.
<> COMPRESSOR REMOVAL
Take care not to spill any compressor oil when removing the
compressor.
INSTALLATION SERVICE POINT
.
>>A<< FLEXIBLE SUCTION HOSE CONNECTION
To prevent mis-alignment of suction hose to bracket use the
folowing assembly procedure.
1. Insert hoseconnector into compressor and hand start bolt.
2. Assemble P-clip to hose and suction hose bracket. Tighten
bolt.
3. Tighten bolt between compressor and hose connector.
.
>>B<< COMPRESSOR INSTALLATION
If a new compressor is installed, first adjust the amount of oil
according to the procedures described below, and then install
the compressor.
1. Measure the amount (X ml) of oil within the removed
compressor.
2. Drain (from the new compressor) the amount of oil
calculated according to the following formula, and then
install the new compressor.
New compressor oil amount = 140 ml
140 ml
X ml = Y ml
NOTE: Y ml indicates the amount of oil in the refrigerant line,
the condenser, the evaporator, etc.
NOTE: When replacing the following parts at the same times as
the compressor, subtract the rated oil amount of each part from
Y ml and discharge from the new compressor.
Compressor oil: ND Oil 8
Quantity:
Evaporator: 40 ml
Condenser: 40 ml
Receiver: 40 ml
Page 869 of 1500
Page 870 of 1500
CONDENSER AND CONDENSER FAN
HEATER, AIR CONDITIONING AND VENTILATION55-169
>>B<< CONDENSER INSTALLATION
When replacing the condenser, refill it with a specified amount
of compressor oil and install it to the vehicle.
Compressor oil: ND Oil 8
Quantity: 40 ml
INSPECTIONM1552014301102
CONDENSER FAN MOTOR CHECK
Check to be sure that the condenser fan motor operates when
battery voltage is applied to terminal 2 and terminal 1
grounded.
Page 872 of 1500