1998 NISSAN PICK-UP Repair Manual

Performance Chart
TEST CONDITION
Testing must be performed as follows:
Vehicle location: Indoors or in the shade (in a well-
venti lated place)
Doors: Closed
Door window: Open
Hood: Open
TEMP. setting: Max. COLD
Discharge Air: FACE VENT
INTAKE lever position:
(Recirculation)
FAN speed: 4-speed
Engine speed: 1,500 rpm
Operate the air conditioner system for 10 minutes before taking
measurements.
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)
50-6020 (68) 6.6 - 9.4 (44 - 49)
25 (77) 9.6 - 11.8 (49 - 53)
30 (86) 13.5 - 16.5 (56 - 62)
35 (95) 17.5 - 21.2 (64 - 70)
40 (104) 21.4 - 25.9 (71 - 79)
60-7020 (68) 9.4 - 11.2 (49 - 52)
25 (77) 11.8 - 14.1 (53 - 57)
30 (86) 16.5 - 19.5 (62 - 67)
35 (95) 21.2 - 24.9 (70 - 77)
40 (104) 25.9 - 30.3 (79 - 87)
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)
50-7020 (68)971 - 1,187 (9.71 - 11.87,
9.9 - 12.1, 141 - 172)59 - 69 (0.59 - 0.69,
0.6 - 0.7, 9 - 10)
25 (77)991 - 1,206 (9.91 - 12.06,
10.1 - 12.3, 144 - 175)69 - 78 (0.69 - 0.78,
0.7 - 0.8, 10 - 11)
30 (86)1,187 - 1,442 (11.87 - 14.42,
12.1 - 14.7, 172 - 209)88 - 108 (0.88 - 1.08,
0.9 - 1.1, 13 - 16)
35 (95)1,402 - 1,716 (14.02 - 17.16,
14.3 - 17.5, 203 - 249)108 - 127 (1.08 - 1.27,
1.1 - 1.3, 16 - 18)
40 (104)1,628 - 1,981 (16.28 - 19.81,
16.6 - 20.2, 236 - 287)127 - 157 (1.27 - 1.57,
1.3 - 1.6, 18 - 23)
TROUBLE DIAGNOSES
HA-26

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
standard (normal) pressure differs from vehicle to vehicle, refer to HA-26 (``Ambient air temperature-to-op-
erating pressure table'').
Gauge indication Refrigerant cycle Probable cause Corrective action
Both high and low-pressure
sides are too high.
AC359A
lPressure is reduced soon
after water is splashed on
condenser.Excessive refrigerant charge in
refrigeration cycle.Reduce refrigerant until speci-
fied pressure is obtained.
Air suction by cooling fan is
insufficient.Insufficient condenser cooling
performance.
¯
V1Condenser fins are
clogged.
V2Improper fan rotation of
cooling fan.
lClean condenser.
lCheck and repair cooling fan
as necessary.
lLow-pressure pipe is not
cold.
lWhen 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.
lAn area of the low-pressure
pipe is colder than areas
near the evaporator outlet.
lPlates are sometimes cov-
ered with frost.
lExcessive liquid refrigerant
on low-pressure side.
lExcessive refrigerant dis-
charge flow.
lExpansion valve is open a
little compared with the speci-
fication.
¯
V1Improper thermal valve
installation.
V2Improper 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.lCheck and repair or replace
malfunctioning parts.
lCheck lubricant for contami-
nation.
TROUBLE DIAGNOSES
HA-27

Gauge indication Refrigerant cycle Probable cause Corrective action
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 operation
is improper.
¯
Damaged inside compressor
packings.Replace compressor.
No temperature difference
between high and low-pressure
sides.Compressor pressure operation
is improper.
¯
Damaged inside compressor
packings.Replace compressor.
Both high and low-pressure
sides are too low.
AC353A
lThere is a big temperature
difference between receiver
drier outlet and inlet. Outlet
temperature is extremely low.
lLiquid tank inlet and expan-
sion valve are frosted.Liquid tank inside is clogged a
little.
lReplace liquid tank.
lCheck lubricant for contami-
nation.
lTemperature of expansion
valve inlet is extremely low
as compared with areas near
liquid tank.
lExpansion valve inlet may be
frosted.
lTemperature difference
occurs somewhere in high-
pressure side.High-pressure pipe located
between liquid tank and expan-
sion valve is clogged.
lCheck and repair malfunc-
tioning parts.
lCheck lubricant for contami-
nation.
lExpansion valve and liquid
tank are warm or only cool
when touched.Low refrigerant charge.
¯
Leaking fittings or components.Check refrigerant for leaks.
Refer to ``Checking Refrigerant
Leaks'', HA-56.
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.
¯
V1Improper expansion valve
adjustment.
V2Malfunctioning thermal
valve.
V3Outlet and inlet may be
clogged.
lRemove foreign particles by
using compressed air.
lCheck lubricant for contami-
nation.
An area of the low-pressure
pipe is colder than areas near
the evaporator outlet.Low-pressure pipe is clogged
or crushed.
lCheck and repair malfunc-
tioning parts.
lCheck lubricant for contami-
nation.
Air flow volume is not enough
or is too low.Compressor pressure operation
is improper.Replace compressor.
TROUBLE DIAGNOSES
Trouble Diagnoses for Abnormal Pressure
(Cont'd)
HA-28

Gauge indication Refrigerant cycle Probable cause Corrective action
Low-pressure side sometimes
becomes negative.
AC354A
lAir conditioner system does
not function and does not
cyclically cool the compart-
ment air.
lThe 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 expansion
valve outlet and inlet.
¯
Water is mixed with refrigerant.
lDrain water from refrigerant
or replace refrigerant.
lReplace liquid tank.
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.Leave the system at rest. Start
it again to check whether or not
the problem is caused by water
or foreign particles.
lIf water is the cause, initially
cooling is okay. Then the
water freezes, causing a
blockage. Drain water from
refrigerant or replace refriger-
ant.
lIf due to foreign particles,
remove expansion valve and
remove the particles with dry
and compressed air.
lIf either of the above meth-
ods cannot correct the
problem, replace expansion
valve.
lReplace liquid tank.
lCheck lubricant for contami-
nation.
TROUBLE DIAGNOSES
Trouble Diagnoses for Abnormal Pressure
(Cont'd)
HA-29

Component Location
RHA371GA
TROUBLE DIAGNOSES
HA-30

Wiring Diagram Ð HEATER Ð
HHA100
.
HAþHEATERþ01
TROUBLE DIAGNOSES
HA-31

Circuit Diagram Ð Air Conditioner
HHA129
TROUBLE DIAGNOSES
HA-32

Wiring Diagram Ð A/C Ð
HHA133
.
HAþA/C, Mþ01
.To
HAþA/C, Mþ03
TROUBLE DIAGNOSES
HA-33