92Rocky-AC-Air_Conditioning_System-Part1
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PART 1 - PART 2 - PART 3 - PART 4 - PART 5 - PART 6
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DAIHATSU
Rocky
AIR CONDITIONING SYSTEM
GENERAL DESCRIPTION AC- 2 PRECAUTIONS AC- 4 SPECIAL TOOLS AND EQUIPMENT AC- 4 TROUBLE SHOOTING AC- 5 CHECKING OF REFRIGERATION SYSTEM
WITH MANIFOLD GAUGE AC- 6 IN-VEHICLE INSPECTION AC-11 REFRIGERATION SYSTEM AC-12 CHECKING OF REFRIGERANT
CHARGE AC-12 INSTALLATION OF MANIFOLD
GAUGE SET AC-12 EVACUATING AND CHARGING OF
REFRIGERATION SYSTEM AC-13 WIRING DIAGRAM AC-21 SYSTEM COMPONENTS AC-23 COMPRESSOR AC-24
CONDENSER AC-38 RECEIVER AC-39 COOLING UNIT AC-40 EVAPORATOR AC-42 REFRIGERANT LINES AC-43 THERMISTOR AC-44 DUAL PRESSURE SWITCH AC-45 A/C SWITCH AC-46 CONDENSER FAN MOTOR AC-47 CONDENSER FAN RELAY AC-47 FUSIBLE LINK AC-47 WATER TEMPERATURE SWITCH AC-48 AIR CONDITIONER AMPLIFIER AC-49 AIR CONDITIONER CUT-OFF
AMPLIFIER AO-51 VACUUM SWITCHING VALVE (VSV) AC-52 ADJUSTMENT OF ENGINE A/C RPM ..
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AIR CONDITIONING SYSTEM
Discharge port Suction port REFRIGERATION CYCLE
Expansion valve
0
the evaporator plus the neat created by the compressor in the discharge stroke. This gaseous refrigerant flows into the condenser. In the condenser the gaseous refrigerant condenses into liquid refrigerant. 3. This iiquid refrigerant flows into the receiver which stores and filters the liquid refrigerant till the evaporator requires the refrigerant.
pressure refrigerant that contains the heat absorbed from
2. This oaseous refrioerant flows into the condenser. In the *£10
Evaporator
4. At the expansion valve the liquid refrigerant changes into low temperature lovv pressure liquid and
refrigerant mixture. 5. This cold refrigerant flows into the evaporator. The heat from the warm air stream passing through the evaporator core is transferred to the refrigerant. All the liquid is change into the gaseous refrigerant in the evaporator and only heat-laden gaseous refrigerant is drawn into the compressor. Then the process
is repeated again.
WRU90-AC002
31)
the evaporator tubes. It then removes heat from the air blowing across the fins and tubes and evaporates causing the temperature inside the car gradually to be lowered.
evaporator cores causing a drop in pressure and consequently drop in
temperature.
(1) COMPRESSOR draws oil 1 gaseous refrrgeranl from the evaporator and compresses 11, This causes the refigeranl gas temperature and pressure to nse randly.
_.JR ‘E 1
RECEIVER removes any
traces of moisture and filters out dirt in the system. It also serves as a reservoir for t excessive refrigerant.
Iiquied.
(2) CONDENSER through which the heated remgerant gas gives off heat tothe engme cooling air. The refrigerant gas cools off and once again becomes a
AC-2
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AIR CONDITIONING SYSTEM
1. PRINCIPLE OF A/C ELECTRICAL CIRCUIT
switch HUD.; motor
L_ Acclerating cut switch
if Water temp.
switch
amp
Battery Fuse r__h A/Cisiiich Thermistor wa (gg V1 Mfg %
Fuse f-1
IG. switch
Dual pressure
Revolution detecting
HOW MAGNETIC CLUTCH BE ENERGIZED
2.
The general process until magnetic clutch is energized is shown below.
1. Ignition Switch “ON” 2. Blower Switch "ON"
Heater Relay “ON” (Blower Motor “RUN”) 3. A/C Switch “ON”
A/C Cut Amplifier “ON" A/C Amplifier “ON” 4. Dual Pressure Switch “ON”
Refrigerant Condition: 2.1 kg/cmz (30 psi) - 27 kg/cmz (384 psi)
5. Thermistor suppiys the signal for temperature of evaporator to amplifier.
6. VSV “ON” Engine idle up. 7. Magnetic Clutch “ON”
AC-3
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AIR CONDITIONING SYSTEM
PRECAUTIONS
1. When handling refrigerant (R-12), the following precautions should be observed:
(1) Always wear goggles.
(2) Keep the refrigerant container (service drum) below 40°C (i04°F). (3) Do not handle refrigerant in an enclosed area where there is an open flame. (4) Discharge refrigerant slowly when purging the system. (5) Be careful that liquid refrigerant does not get on your skin. 2. if liquid refrigerant gets in the eyes or on the skin:
(1) Do not rob. (2) Wash the area with a lot of cool water.
(3) Rush to physician or hospital for immediate professional treatment.
(4) Do not attempt to treat yourself. 3. When connecting the refrigerant lines:
(1) Apply a few drops of compressor oil onto the O-ring fittings.
(2) Tighten the nut using two wrenches to avoid twisting the tube.
(3) Tighten the O-ring fitting to the specified torque.
Tightening torque for O-ring fittings and bolted type fittings.:
Fitting size
Tightening torque
0.31 inch Tube
0.50 inch Tube
0.62 inch Tube
F C Bolted Type ' ( or ompressor)
5.4(For Receiver)
SPECIAL TOOLS AND EQUIPMENT
Name
Use
Air-conditioner magnet clutch stopper
To remove and install pressure plate
Air-conditioner magnet clutch remover
To remove pressure plate
TOO' Air-conditioner bit set
To remove service valve and front housing
Air-conditioner seal plate replacer
To replace seal plate
Air-Conditioner seal plate remover
To remove seal plate
Manifold gauge set
To evacuate and charge system
Equipment Ohm meter
T0 diagnosis electrical system
Voltage meter
To diagnosis electrical system
AC-4
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TROUBLE SHOOTING
You will find the troubles easier using the table well shown below. In this table, each number shows the priority of causes in trouble. Check each part in order.
See page
Trouble
ration
No blower ope
No compressor
operation
Compressor operate ntermittently
Volume of refrigeranf 1 1
Drive belt tension
AC-47
Fusibke link
BE-111
Heater relay 1 2
BE-109
Blower switch 2
AC-47
Condenser fan relay 2
Condenser fan motor 3
AC-24
Compressor 1 1
AC-24
Magnétic clutch 10
AC-28
Revolution detecting Sensor 12 (With P/S model)
Dual pressure switch 4 4
Thermistor 5 5
Water temperature switch 6
Throttle switch 7
A/C amplifier 8 6
A/C out-off amplifier 9 7
Condenser
Receiver
Evaporator
Expansion valve
Vacuum switching valve (VSV)
Wiring & its connection 12 8
AIR CONDITIONING SYSTEM
OITIGS OUt
engine idle up n A/C switch on
T COFTISS OUT
comes out
No condenser fan
operatio
ne
9
eng
coonn
only at high
No coo
ntermitt
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AIR CONDITIONING SYSTEM
CHECKING OF REFRIGERATION SYSTEM WITH MANIFOLD GAUGE
This is a method in which the trouble is located by using a
manifoid gauge.
Read the manifold gauge pressure with the following estab
lished conditions:
(1) Temperature at the air inlet is 30 - 35°C (86 - 95°F) (2) Engine running at 1,500 rpm
(3) Blower speed set at high (4) Temperature control lever
NOTE:
v It should be noted that the gauge indications may vary
set at cool
slightly due to ambient temperature conditions.
1. Normally functioning refrigeration system
Gauge Reading:
Low pressure side
2. Moisture present in refrigeration system
Condition:
Periodically cools and then fails to cool
Symptom seen in refrigeration system
Probable cause I Diagnosis Remedy
During operation, pressure at low pressure side sometimes becomes a vacuum and sometimes normal
(1) Replace receiver and
restgred after a time when cirfulation of (3) ‘refrigerant to the |ce melts re ngeran proper amount
AC-6
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AIR CONDITIONING SYSTEM
3. Insufficient refrigerant
Condition: insufficient cooling
_. E__JQ
E
Symptom seen in | | _ Afrinnmfinn ex/emm Probable Cause Dlag
nosis 4 Remedy
Symptom seen in refrigeration system
Insufficient refrigerant in I (1) Check with leak
Pressure low at both low | Gas ieakage at some place g
in refrigeration system | system I detector and repair
(2) Charge refrigerant to
and high pressure sides
igerant leaking | proper amount
Bubbles seen in sight glass
Refrigerant leaking
Insufficient cooling
_ wauso-Acom
performance
4. Poor circulation of refrigerant _ Condition: Insufficientcooling .-- W Ka' K n A
Symptom seen in refrigeration system
Probable cause
F Diagnosis Remedy
ed | Receiver clogged
Replace: receiver
Pressure low at both low and high pressure sides
Frost on tubes from receiver to unit
Refrigerant flow obstruct by dirt in receiver
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AIR CONDITIONING SYSTEM
5. Refrigerant overcharge or insufficient cooling of con
denser Condition: Does not cool sufficiently
IE
Symptom seen in
Diagnosis
Remedy
Pressure too high at both iow and high pressure sides
Unable to develop sufficient performance due to excessive refrigerant in system
Condenser cooling insufficient
Excessive refrigerant in cycle -> refrigerant overcharged
Condenser cooling
faulty
insufficient -> condenser fins clogged or fan motor
(1) Clean condenser (2) Check fan motor
operation (3) If (1) and (2) are
normal, check amount of refrigerant
NOTE: Vent out refrigerant through gauge manifold iow pressure :side by gradually opening valve.
6. Expansion valve improperly mounted/heat sensing
tube defective (opens too wide) Condition: Insufficient cooling /
"1, ._ _A 2
Symptom seen in refrigeration system I Probabie Cause
Diagnosis
Remedy
Pressure too high at both | Trouble in expansion valve I Excessive refrigerant in low
low and high pressure sides | or heat sensing tube not
installed correctly
Frost or large amount of 1 § Expansion valve opened
dew on piping at low | Refrigerant flow out of pressure side | adjustment
pressure piping
too wide
(1) Check heat sensing
tube installed condition
(2) If (1) is normal. test
expansion valve in unit
Repiace if defective
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AIR CONDITIONING SYSTEM
Air present in refrigeration system
Condition: Does not cool sufficiently A NOTE; 2 . 1 » - These gauge indications are shown when the refrigera- .. :_ :L
tion system has been opened and the refrigerant E charged without vacuum purging. f A ,
Symptom seen in
Pressure too high at both Air entered refrigeration Air present in refrigeration _ low and high pressure sides I system I system (1) gggace re°e'Verand
Insufficient vacuum purging
(2) Check compressor oil to see If dirty or in- , sufficient (3) Vacuum purge and
Charge new refrigerant
Condition:
Does not cool (Coois from time to time in some cases)
8. Refrigerant does not circulate
Symptom seen in refrigeration system
Probable cause
Diagnosis
Remedy
Vacuum indicated at low pressure side and very low pressure Indicated at high pressure side
Frost or dew seen on piping before and after receiver and drier or expansion valve
Refrigerant flow obstructed by moisture or dirt in refrigerant freezing or adhering to expansion valve orifice
Refrigerant flow obstructed by gas leakage from expansion valve heat sensing tube
Expansion valve orifice clogged
Refrigerant cues not few
Allow to :stand for some time and then restart operation to determine if trouble is: caused by moisture or dirt.
If caused by moisture refer to step 2 on page AC-6.
lf caused by dirt, remove expansion valve and clean off dirt by blowing with air. lf unable to remove dirt, replace valve.
Vacuum purge and charge new refrigerant to proper amount.
For gas leakage from heat sensing tube, replace expansion valve.
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AIR CONDITIONING SYSTEM
9. Insufficient compression
Condition: Does not cool
Symptom seen in refrigeration system I Probable Cause
W
Diagnosis
Remedy
Pressure too high at low | Internal leak in compressor
Pressure side
Pressure too low at high Pressure side
Compression defective
Valve leaking or broken sliding parts (Piston, cylinder, gasket, etc.,) broken
Repair or replace compressor
AC-10
