1998 NISSAN PICK-UP engine

Control Operation
FAN CONTROL LEVER
This lever turns the fan ON and OFF, and controls fan speed.
MODE CONTROL LEVER
This lever controls the outlet air flow.
TEMPERATURE CONTROL LEVER
This lever allows adjustment of the temperature of the outlet air.
RECIRCULATION CONTROL LEVER
FRESHposition:
Outside air is drawn into the passenger compartment.
Recirculation (REC)
position:
Interior air is recirculated inside the vehicle.
AIR CONDITIONER SWITCH
The air conditioner switch controls the A/C system. When the switch is depressed with the fan ON, the
compressor will turn ON. The indicator lamp will also light.
The air conditioner cooling function operates only when the engine is running.
RHA345G
DESCRIPTION
HA-16

Operational Check
The purpose of the operational check is to confirm that the sys-
tem operates properly.
CONDITIONS:
lEngine running at normal operating temperature.
PROCEDURE:
1. Check blower
a. Slide fan control lever to 1-speed.
Blower should operate on 1-speed.
b. Slide fan control lever to 2-speed and continue checking
blower speed until all speeds are checked.
c. Leave blower on 4-speed.
2. Check discharge air
a. Slide mode control lever to
position.
b. Confirm that all discharge air comes out of face vents.
c. Slide mode control lever to
position.
d. Confirm that discharge air comes out of face vents and foot
vents.
e. Slide mode control lever to
position.
f. Confirm that discharge air comes out of foot vents, with some
air from defrost vents.
g. Slide mode control lever to
position.
h. Confirm that discharge air comes out of foot vents with some
air from defrost vents.
i. Slide mode control lever to
position.
j. Confirm that all discharge air comes out of defrost vents.
3. Check recirculation
a. Slide recirculation control lever to the REC
position.
b. Listen for intake door position change (you should hear
blower sound change slightly).
RHA346G
RHA347G
RHA348G
TROUBLE DIAGNOSES
HA-18

Preliminary Check
PRELIMINARY CHECK 1
A/C does not blow cold air.
DOES AIR FLOW FROM VENTS?
Condition:
lEngine running at operating tem-
perature.
lIgnition switch, A/C switch, and fan
switch are ON.
lMode control lever is in FACE posi-
tion and temperature control lever
is in full cold position.
Yes
cNo
IS BLOWER MOTOR OPERATING
NORMALLY?
Yes No
CHECK BLOWER
MOTOR OPERATION.
Go toDiagnostic Pro-
cedure 1, HA-37.
CHECK COMPRESSOR BELT TEN-
SION.
Refer to MA section (``Checking
Drive Belts'', ``ENGINE MAINTE-
NANCE'').
NG OKNG
bCHECK COMPRESSOR OPERA-
TION.
OKCHECK FOR EVAPORATOR COIL
FREEZE UP.
Remove intake unit. Check if evapo-
rator freezes.
Adjust or replace com-
pressor belt.CHECK REFRIGERATION CYCLE
PRESSURE WITH MANIFOLD
GAUGE CONNECTED.
Refer to Performance Chart, HA-26.
NG OKNG
(Freezes up.)OK
(Does not
freeze up.)
CHECK REFRIGERANT.
Connect manifold gauge then check
system pressure.
Refer to ``Performance Chart'',
HA-26.
OK NGCHECK VENTILATOR
DUCT FOR AIR
LEAKS.Go toPerformance
Test Diagnoses,
HA-24.CHECK THERMO CONTROL AMP.
OPERATION.
Refer to ``Electrical Components
Inspection'', HA-44.
CHECK FOR REFRIG-
ERANT LEAKS.CHECK WATER COCK OPERA-
TION.
Except for RHD models
Warm up engine before checking.
Refer to ``Control Linkage
Adjustment'', HA-46.
OK
cNG
Adjust or replace water cock.
Go toDiagnostic Procedure 2,
HA-39.CHECK TEMPERATURE CONTROL
CABLE.
Refer to ``Control Linkage
Adjustment'', HA-47.
OK
cNG
Adjust temperature control cable.
VISUALLY INSPECT AIR MIX DOOR.Access by removing instrument
panel.
OK
cNG
Replace air mix door.
CHECK THERMO CONTROL AMP.
OPERATION.
Refer to ``Electrical Components
Inspection'', HA-44.
.
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.
TROUBLE DIAGNOSES
HA-21

PRELIMINARY CHECK 2
Noise
CHECK WHERE NOISE COMES FROM.
Blower motorCompressorExpansion valveRefrigerant lineBelt
CHECK FOR
NOISE IN ALL
MODES AND
TEMPERATURE
SETTINGS.
Noise is
constant
.
Inspect the com-
pressor clutch and
pulley and idler
pulley.
OK NGReplace expan-
sion valve.
CHECK
BLOWER
MOTOR AND
FAN FOR
WEAR.
OK
.
NGReplace com-
pressor clutch
and pulley.
Refer to
HA-60 or 64.
Line is fixed
directly to body.Line is not fixed.
Replace
blower
motor or
fan.CHECK DISC-TO-
PULLEY CLEAR-
ANCE.
Refer to HA-62 or
66.
OKFix line with
rubber or vibra-
tion absorbing
material.
Fix line tightly.
CHECK
BLOWER
MOTOR FOR
FOREIGN PAR-
TICLES.
NGCHECK AND
ADJUST COM-
PRESSOR
LUBRICANT.
Refer to HA-50.OK
Remove foreign
particles from
intake unit.
Replace compres-
sor and liquid
tank.Belt vibration is
intense.Side of belt is
worn out.
Noise is
intermittent
CHECK AIR DIS-
CHARGE DUCTS
FOR OBSTRUC-
TIONS, FOREIGN
MATERIALS OR
AIR LEAKAGE.
.
NGReadjust belt
tension.
Refer to MA
section
(``Checking
Drive Belts'',
``ENGINE
MAINTE-
NANCE'').
Pulley center
does not match.
Readjust pulley
center.
Refer to HA-61 or
65.
Remove obstruc-
tions or repair air
leakage.
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TROUBLE DIAGNOSES
Preliminary Check (Cont'd)
HA-22

PRELIMINARY CHECK 3
Insufficient heating
DOES AIR FLOW FROM FOOT AREA?
Condition:
lVehicle at operating temperature.
lIgnition switch and fan switch are ON.
lMode control lever is in FOOT position and tem-
perature control lever is in full hot position.
Yes
cNoCHECK BLOWER MOTOR
OPERATION.
Go toDiagnostic Procedure
1, HA-37.
Check the following:
lEngine coolant level. Refer to MA section.
lHoses for leaks or kinks.
lRadiator cap. Refer to LC section (``ENGINE
COOLING SYSTEM'').
lAir in cooling system.
OK
cNG
Repair/replace as necessary.
CHECK WATER COCK OPERATION.
Except for RHD models
Warm up engine before checking.
Refer to ``Control Linkage Adjustment'', HA-46.
OK
cNG
Adjust or replace water cock.
CHECK TEMPERATURE CONTROL CABLE.
Refer to ``Control Linkage Adjustment'', HA-47.
OK
cNG
Adjust temperature control
cable.
VISUALLY INSPECT AIR MIX DOOR.
Access by removing instrument panel.
OK
cNG
Replace air mix door.
CHECK BY FEEL HEATER INLET AND OUTLET
HOSES.
Both hoses
coldBoth hoses
warm
CHECK THERMOSTAT
INSTALLATION.
OKCHECK HEATER HOSES FOR
PROPER INSTALLATION.OK
Replace thermostat. Refer
to LC section (``Thermostat'',
``ENGINE COOLING SYS-
TEM'').
Back flush heater core, drain and refill coolant.
Retest.
Hot inlet
Warm outletBoth hoses
warm
System OK
Replace heater
core.
.
.
.
.
.
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TROUBLE DIAGNOSES
Preliminary Check (Cont'd)
HA-23

VA
Malfunctioning blower motor fan.Malfunctioning electrical circuit.Malfunctioning blower motor internal
circuit.
Loose fan/Improper contact of fan
and case/Deformed fan.Discontinued wiring or component
circuits or poor connection/
Malfunctioning resistor, amplifier,
etc./Burned out fuse or low battery
voltage.
VB
Magnet clutch does not engage.Magnet clutch slipping.Belt slipping.
CHECK MAGNET CLUTCH.
Inspect coil circuit, disc-to-pulley
clearance.CHECK COMPRESSOR BELT AND
BELT TENSION. Refer to MA sec-
tion (``Checking Drive Belts'',
``ENGINE MAINTENANCE'').
CHECK ELECTRICAL CIRCUIT.
Inspect wiring, components circuit.cMalfunctioning internal parts of
clutch, compressor.
CHECK ACTIVATION OF SAFETY/
PROTECTION DEVICES. Inspect
devices such as pressure switch,
etc.cForeign particles on clutch frictional
surface or excessive disc clear-
ance.
cMalfunctioning electrical circuit
(poor connection, low battery
voltage, etc.).
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.
.
TROUBLE DIAGNOSES
Performance Test Diagnoses (Cont'd)
HA-25

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