System Description
SWITCH AND THEIR CONTROL FUNCTIONS
Knob/SwitchKnob/Switch position
Air outlet Intake air Compressor
A/C
A/CjÐ Ð ON*
Mode
jVENT Ð Ð
jB/L Ð Ð
jFOOT Ð Ð
jD/F FRE Ð
jDEF FRE ON*
jÐÐÐ
*: Compressor is operated by dual-pressure switch.
Control Operation
FAN CONTROL KNOB
This knob turns the fan ON and OFF, and controls fan speed.
MODE CONTROL KNOB
This knob controls the outlet air ¯ow.
TEMPERATURE CONTROL KNOB
This knob allows adjustment of the temperature of the outlet air.
RECIRCULATION (REC) SWITCH
OFF position: Outside air is drawn into the passenger compartment.
ON position: Interior air is recirculated inside the vehicle. The indicator lamp will also light.
AIR CONDITIONER SWITCH
The air conditioner switch controls the A/C system. When the switch is depressed with the fan ON, the com-
pressor will turn ON. The indicator lamp will also light.
The air conditioner cooling function operates only when the engine is running.
RHA582G
DESCRIPTIONMANUAL
HA-16
How to Perform Trouble Diagnoses for Quick
and Accurate Repair
WORK FLOW
*1: HA-22
SYMPTOM TABLE
Symptom Reference page
+Intake door does not change.+Go to Trouble Diagnosis Procedure for Intake Door
Motor Circuit.HA-24
+Blower motor does not rotate at all.+Go to Trouble Diagnosis Procedure for Blower Motor
Circuit.HA-28
+Insufficient cooling.+Go to Trouble Diagnosis Procedure for Insufficient
Cooling.HA-32
+Insufficient heating.+Go to Trouble Diagnosis Procedure for Insufficient
Heating.HA-32
+Air outlet does not change.+Go to Trouble Diagnosis Procedure for Air Outlet. HA-41
+Magnet clutch does not engage when A/C switch and
fan switch are ON.+Go to Trouble Diagnosis Procedure for Magnet Clutch
Circuit.HA-43
+Noise+Go to Trouble Diagnosis Procedure for Noise. HA-48
SHA900E
TROUBLE DIAGNOSESMANUAL
HA-21
PERFORMANCE CHART
Test condition
Testing must be performed as follows:
Vehicle location: Indoors or in the shade (in a well-ventilated place)
Doors: Closed
Door window: Open
Hood: Open
TEMP.: Max. COLD
Discharge Air: Face Vent
REC switch: (Recirculation) set
FAN speed: High speed
Engine speed: Idle speed
Operate the air conditioning system to 10 minutes before taking
measurements.
Rear cooler: ON (For rear cooler equipped model only)
Test reading (Single A/C equipped model)
Recirculating-to-discharge air temperature table
Inside air (Recirculating air) at blower assembly inlet
Discharge air temperature at center ventilator ÉC (ÉF)
Relative humidity % Air temperature ÉC (ÉF)
50-6025 (77) 8.0 - 10.0 (46 - 50)
30 (86) 12.0 - 15.0 (54 - 59)
35 (95) 16.0 - 20.0 (61 - 68)
40 (104) 20.5 - 24.5 (69 - 76)
60-7025 (77) 10.4 - 13.0 (51 - 55)
30 (86) 15.0 - 18.0 (59 - 64)
35 (95) 19.5 - 23.4 (67 - 74)
40 (104) 24.5 - 28.5 (76 - 83)
Ambient air temperature-to-operating pressure table
Ambient air
High-pressure (Discharge side)
kPa (bar, kg/cm
2, psi)Low-pressure (Suction side)
kPa (bar, kg/cm2, psi)
Relative humidity %Air temperature
ÉC (ÉF)
50-7025 (77)1,373 - 1,471 (13.73 - 14.71,
14.0 - 15.0, 199 - 213)196 - 245 (1.96 - 2.45,
2.0 - 2.5, 28 - 36)
30 (86)1,275 - 1,520 (12.75 - 15.20,
13.0 - 15.5, 185 - 220)226 - 284 (2.26 - 2.84,
2.3 - 2.9, 33 - 41)
35 (95)1,412 - 1,716 (14.12 - 17.16,
14.4 - 17.5, 205 - 249)255 - 314 (2.55 - 3.14,
2.6 - 3.2, 37 - 46)
40 (104)1,608 - 1,932 (16.08 - 19.32,
16.4 - 19.7, 233 - 280)294 - 353 (2.94 - 3.53,
3.0 - 3.6, 43 - 51)
TROUBLE DIAGNOSESMANUAL
Insufficient Cooling (Cont'd)
HA-35
Trouble Diagnoses for Abnormal Pressure
Whenever system's high or low-pressure side is abnormal, diagnose using a manifold gauge. The marker
above the gauge scale in the following table indicates the standard (normal) pressure range. Since the stan-
dard (normal) pressure differs from vehicle to vehicle, refer to HA-35 (``Ambient air temperature-to-operating
pressure table'').
Gauge indication Refrigerant cycle Probable cause Corrective action
Both high and low-pressure
sides are too high.
AC359A
+Pressure is reduced soon
after water is splashed on
condenser.Excessive refrigerant charge in
refrigeration cycle.Reduce refrigerant until speci-
®ed pressure is obtained.
Air suction by cooling fan is
insufficient.Insufficient condenser cooling
performance.
¯
j
1Condenser ®ns are clogged.
j
2Improper fan rotation of
cooling fan.+Clean condenser.
+Check and repair cooling fan
as necessary.
+Low-pressure pipe is not
cold.
+When compressor is stopped
high-pressure value quickly
drops by approximately 196
kPa (2.0 bar, 2 kg/cm
2,28
psi). It then decreases gradu-
ally thereafter.Poor heat exchange in con-
denser.
(After compressor operation
stops, high pressure decreases
too slowly.)
¯
Air in refrigeration cycle.Evacuate repeatedly and
recharge system.
Engine tends to overheat. Engine cooling systems mal-
function.Check and repair each engine
cooling system.
+An area of the low-pressure
pipe is colder than areas
near the evaporator outlet.
+Plates are sometimes cov-
ered with frost.+Excessive liquid refrigerant
on low-pressure side.
+Excessive refrigerant dis-
charge ¯ow.
+Expansion valve is open a
little compared with the
speci®cation.
¯
j
1Improper thermal valve
installation.
j
2Improper expansion valve
adjustment.Replace expansion valve.
High-pressure side is too high
and low-pressure side is too
low.
AC360A
Upper side of condenser and
high-pressure side are hot,
however, liquid tank is not so
hot.High-pressure tube or parts
located between compressor
and condenser are clogged or
crushed.+Check and repair or replace
malfunctioning parts.
+Check lubricant for contami-
nation.
TROUBLE DIAGNOSESMANUAL
HA-36
How to Perform Trouble Diagnoses for Quick
and Accurate Repair
WORK FLOW
*1: Operational Check (HA-70)
SYMPTOM TABLE
Symptom Reference page
+A/C system does not come on.+Go to Trouble Diagnosis Procedure for A/C system. HA-73
+Air outlet does not change.
+Go to Trouble Diagnosis Procedure for Mode Door Motor.
(LAN).HA-75
+Mode door motor does not operate nor-
mally.
+Discharge air temperature does not
change.
+Go to Trouble Diagnosis Procedure for Air Mix Door Motor
(LAN).HA-79
+Air mix door motor does not operate nor-
mally.
+Intake door does not change.
+Go to Trouble Diagnosis Procedure for Intake Door Motor. HA-82
+Intake door motor does not operate nor-
mally.
+Blower motor operation is malfunctioning.
+Go to Trouble Diagnosis Procedure for Blower Motor. HA-86
+Blower motor operation is malfunctioning
under out of starting fan speed control.
+Magnet clutch does not engage.+Go to Trouble Diagnosis Procedure for Magnet Clutch. HA-92
+Insufficient cooling.+Go to Trouble Diagnosis Procedure for Insufficient Cooling. HA-98
+Insufficient heating.+Go to Trouble Diagnosis Procedure for Insufficient Heating. HA-99
+Noise.+Go to Trouble Diagnosis Procedure for Noise. HA-100
+Self-diagnosis cannot be performed.+Go to Trouble Diagnosis Procedure for Self-diagnosis. HA-101
+Memory function does not operate.+Go to Trouble Diagnosis Procedure for Memory Function. HA-102
SHA900E
TROUBLE DIAGNOSESAUTO
HA-69
Blower speed compensation
Sunload
When the in-vehicle temperature and the set temperature are very close, the blower will be operating at low
speed. The low speed will vary depending on the sunload. During conditions of high sunload, the blower low
speed is ``normal'' low speed (approx. 6V). During low or no sunload conditions, the low speed will drop to
``low'' low speed (approx. 5V).
Ambient
When the ambient temperature is in the ``moderate'' range [10 þ 15ÉC], the computed blower voltage will be
compensated (reduced) by up to 3.5V (depending on the blower speed). In the ``extreme'' ambient ranges
[below 0ÉC and above 20ÉC] the computed objective blower voltage is not compensated at all. In the ambi-
ent temperature ranges between ``moderate'' and ``extreme'' [0 - 10ÉC and 15 - 20ÉC], the amount of compen-
sation (for a given blower speed) varies depending on the ambient temperature.
Fan speed control speci®cation
COMPONENT DESCRIPTION
Fan control ampli®er
The fan control ampli®er is located on the cooling unit. The fan
control amp. receives a gate voltage from the auto amp. to step-
lessly maintain the blower fan motor voltage in the 5 to 12 volt
range (approx.).
RHA694G
RHA695G
TROUBLE DIAGNOSESAUTO
Blower Motor (Cont'd)
HA-88
3. Move probe along component approximately 25 to 50 mm (1 to
2 in)/sec.
CHECKING PROCEDURE
To prevent inaccurate or false readings, make sure there is no
refrigerant vapor or tobacco smoke in the vicinity of the
vehicle. Perform the leak test in calm area (low air/wind move-
ment) so that the leaking refrigerant is not dispersed.
1. Turn engine off.
2. Connect a suitable A/C manifold gauge set to the A/C service
ports.
3. Check if the A/C refrigerant pressure is at least 345 kPa (3.452
bar, 3.52 kg/cm
2, 50 psi) above 16ÉC (61ÉF). If less than
speci®cation, evacuate and recharge the system with the speci-
®ed amount of refrigerant.
NOTE: At temperatures below 16ÉC (61ÉF), leaks may not be
detected since the system may not reach 345 kPa
(3.452 bar, 3.52 kg/cm
2, 50 psi).
4. Conduct the leak test from the high side to the low side at points
in alphabetical order (j
a,jb......). Refer to HA-117.
Perform a leak check for the following areas carefully. Clean the
component to be checked and move the leak detector probe
completely around the connection/component.
+Compressor
Check the ®tting of high and low pressure hoses, relief valve
and shaft seal.
+Liquid tank
Check the pressure switch, tube ®tting, weld seams and the
fusible plug mounts.
+Service valves
Check all around the service valves. Ensure service valve caps
are secured on the service valves (to prevent leaks).
NOTE: After removing A/C manifold gauge set from service
valves, wipe any residue from valves to prevent any
false readings by leak detector.
+Cooling unit (Evaporator)
Turn blower fan on ``High'' for at least 15 seconds to dissipate
any refrigerant trace in the cooling unit. Insert the leak detector
probe into the drain hose immediately after stopping the
engine. (Keep the probe inserted for at least ten seconds.)
5. If a leak detector detects a leak, verify at least once by blowing
compressed air into area of suspected leak, then repeat check.
6. Do not stop when one leak is found. Continue to check for
additional leaks at all system components.
7. Start engine.
8. Set the heater A/C control as follows:
a. A/C switch ON
b. Face mode
c. Recirculation switch ON
d. Max cold temperature
e. Fan speed high
SHA708EA
SERVICE PROCEDURESMANUAL AND AUTO
Checking Refrigerant Leaks (Cont'd)
HA-120