system NISSAN TERRANO 2002 Service Repair Manual

4. Check temperature decrease
1) Turn TEMPERATURE CONTROL DIAL to full cold (counter-
clockwise).
2) Check for cold air at discharge air outlets.
5. Check temperature increase
1) Turn TEMPERATURE CONTROL DIAL to full hot (clockwise).
2) Check for hot air at discharge air outlets.
6. Check A/C switch
Turn FAN CONTROL DIAL to the desired position (1 to 4) and
switch AIR CONDITIONER SWITCH to turn ON air conditioner.
Indicator light will come on when air conditioner is ON.
NHA336
NHA337
NHA338
DIAGNOSES Ð Overall System
Operation Check (Cont'd)
HA-29

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 (Front driver side only)
Hood: Open
TEMP. control lever position: Max. COLD
AIR control lever position:
(Ventilation)
INTAKE lever position:
(Recirculation)
FAN lever: 4
Engine speed: 1,500 rpm
Time required before starting testing
after air conditioner starts operating:More than 10 minutes
TEST READING
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)
40-6025 (77) 9.8 - 11.5 (50 - 53)
30 (86) 13.8 - 15.9 (57 - 61)
35 (95) 17.9 - 20.3 (64 - 69)
60-8025 (77) 11.5 - 13.3 (53 - 56)
30 (86) 15.9 - 18.0 (61 - 64)
35 (95) 20.3 - 22.7 (69 - 73)
Ambient air temperature-to-compressor 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)
40-8025 (77)1,451 - 1,608 (14.51 - 16.08,
14.8 - 16.4, 210 - 233)157 - 186 (1.57 - 1.86, 1.6 - 1.9,
23 - 27)
30 (86)1,569 - 1,804 (15.69 - 18.04,
16.0 - 18.4, 228 - 262)176 - 235 (1.76 - 2.35, 1.8 - 2.4,
26 - 34)
35 (95)1,834 - 2,138 (18.34 - 21.38,
18.7 - 21.8, 266 - 310)226 - 304 (2.26 - 3.04, 2.3 - 3.1,
33 - 44)
DIAGNOSES Ð Overall System
HA-30

Performance Test Diagnoses
INSUFFICIENT COOLING
MHA176B
DIAGNOSES Ð Overall System
HA-31

TROUBLE DIAGNOSES FOR ABNORMAL PRESSURE
Whenever abnormal pressure of high and/or low sides of the system is noted, diagnosis must be conducted
by using a manifold gauge. The large-line zone on the gauge scale (see illustrations.) shown in the following
table refers to the standard (normal) pressure range for the corresponding pressure side (high or low). Since
the standard (normal) pressure, however, differs from vehicle to vehicle, refer to the ªAmbient air temperature-
to-compressor pressure tableº.
Gauge indication Refrigerant cycle Probable cause Corrective action
Both high- and low-pressure
sides are too high.
AC359A
IPressure is reduced soon
after water is splashed on
condenser.Excessive refrigerant charge in
refrigeration cycleReduce refrigerant until speci-
fied pressure is obtained.
Air suction by radiator or con-
denser fan is insufficient.Insufficient condenser cooling
performance
"
q
1Condenser fins are clogged.
q
2Improper rotation of radiator
fan or condenser fanIClean condenser.
ICheck and repair radiator or
condenser fan as necessary.
ILow-pressure pipe is not
cold.
IWhen compressor is stopped
high-pressure value quickly
drops by approximately 196
kPa (2 kg/cm
2, 28 psi). It
then decreases gradually
thereafter.Poor heat exchange in con-
denser
(After compressor operation
stops, high pressure
decreases too slowly.)
"
Air in refrigeration cycleEvacuate repeatedly and
recharge system.
Engine tends to overheat. Engine cooling systems mal-
function.Check and repair each engine
cooling system.
IAreas near low-pressure
pipe connection and service
valves are considerably cold
compared with areas near
expansion valve outlet or
evaporator.
IPlates are sometimes cov-
ered with frost.IExcessive liquid refrigerant
on low-pressure side
IExcessive refrigerant dis-
charge flow
IExpansion valve is open a
little compared with the
specification.
"
q
1Improper thermal valve
installation
q
2Improper expansion valve
adjustmentReplace expansion valve.
DIAGNOSES Ð Overall System
Performance Test Diagnoses (Cont'd)
HA-32

Gauge indication Refrigerant cycle Probable cause Corrective action
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.ICheck and repair or replace
malfunctioning parts.
ICheck compressor oil for
contamination.
High-pressure side is too low
and low-pressure side is too
high.
AC356A
High- and low-pressure sides
become equal soon after com-
pressor operation stops.Compressor pressure opera-
tion is improper.
"
Damages inside compressor
packingsReplace compressor.
No temperature difference
between high- and low-pres-
sure sidesCompressor discharge capac-
ity does not change. (Com-
pressor stroke is set at maxi-
mum.)Replace compressor.
Both high- and low-pressure
sides are too low.
AC353A
IThere is a big temperature
difference between liquid
tank outlet and inlet. Outlet
temperature is extremely
low.
ILiquid tank inlet and expan-
sion valve are frosted.Liquid tank inside is clogged a
little.IReplace liquid tank
ICheck compressor oil for
contamination.
ITemperature of expansion
valve inlet is extremely low
as compared with areas near
liquid tank.
IExpansion valve inlet may
be frosted.
ITemperature difference
occurs somewhere in high-
pressure sideHigh-pressure pipe located
between liquid tank and
expansion valve is clogged.ICheck and repair malfunc-
tioning parts.
ICheck compressor oil for
contamination.
DIAGNOSES Ð Overall System
Performance Test Diagnoses (Cont'd)
HA-33

Gauge indication Refrigerant cycle Probable cause Corrective action
Both high- and low-pressure
sides are too low.
AC353A
There is a big temperature dif-
ference between expansion
valve inlet and outlet while the
valve itself is frosted.Expansion valve closes a little
compared with the specifica-
tion.
"
q
1Improper expansion valve
adjustment
q
2Malfunctioning thermal valve
q
3Outlet and inlet may be
clogged.IRemove foreign particles by
using compressed air.
ICheck compressor oil for
contamination.
Areas near low-pressure pipe
connection and service valve
are extremely cold as com-
pared with areas near expan-
sion valve outlet and evapora-
tor.Low-pressure pipe is clogged
or crushed.ICheck and repair malfunc-
tioning parts.
ICheck compressor oil for
contamination.
Air flow volume is not enough
or is too low.Evaporator is frozen.
"
Compressor discharge capac-
ity does not change. (Com-
pressor stroke is set at maxi-
mum length.)Replace compressor.
Low-pressure side sometimes
becomes negative.
AC354A
IAir conditioning system does
not function and does not
cyclically cool the compart-
ment air.
IThe system constantly func-
tions for a certain period of
time after compressor is
stopped and restarted.Refrigerant does not discharge
cyclically.
"
Moisture is frozen at expan-
sion valve outlet and inlet.
"
Water is mixed with refrigerant.IDrain water from refrigerant
or replace refrigerant.
IReplace liquid tank.
DIAGNOSES Ð Overall System
Performance Test Diagnoses (Cont'd)
HA-34

Gauge indication Refrigerant cycle Probable cause Corrective action
Low-pressure side becomes
negative.
AC362A
Liquid tank or front/rear side of
expansion valve's pipe is
frosted or dewed.High-pressure side is closed
and refrigerant does not flow.
"
Expansion valve or liquid tank
is frosted.After the system is left at rest,
start it again in order to con-
firm whether or not problem is
caused by water or foreign
particles.
IIf the problem is due to
water, drain water from
refrigerant or replace refrig-
erant.
IIf it is due to foreign
particles, remove expansion
valve and remove them with
dry and compressed air.
IIf either of the above meth-
ods cannot correct the
problem, replace expansion
valve.
IReplace liquid tank.
ICheck compressor oil for
contamination.
DIAGNOSES Ð Overall System
Performance Test Diagnoses (Cont'd)
HA-35

Harness Layout for A/C System
LH DRIVE MODELS
YHA404
TROUBLE DIAGNOSES
HA-39

RH DRIVE MODELS
YHA405
TROUBLE DIAGNOSES
Harness Layout for A/C System (Cont'd)
HA-40

Main Power Supply and Ground Circuit Check
POWER SUPPLY CIRCUIT CHECK FOR A/C SYSTEM
Check power supply circuit for air conditioning system.
Refer to ªPOWER SUPPLY ROUTINGº in EL section and ªWir-
ing Diagramº.
THERMO CONTROL AMP. CHECK
Check power supply circuit for thermo control amp. with ignition
switch ON.
1. Disconnect thermo control amp. harness connector.
2. Connect voltmeter from harness side.
3. Measure voltage across terminal No.q
1and body ground.
Voltmeter terminal
Voltage
!@
q
1Body ground Approx. 12V
Check body ground circuit for thermo control amp. with A/C switch
ON and fan switch ON.
1. Disconnect thermo control amp. harness connector.
2. Connect ohmmeter from harness side.
3. Check for continuity between terminal No.q
3and body ground.
Ohmmeter terminal
Continuity
!@
q
3Body ground Yes
YHA406
YHA407
TROUBLE DIAGNOSES
HA-51