cooling NISSAN NAVARA 2005 Repair Workshop Manual

MTC-72
TROUBLE DIAGNOSIS
SYSTEM DESCRIPTION
Component Parts
lFront air control
lBlower switch
lBlower motor resistor
lBlower motor
lBlower motor relay
System Operation
Blower Speed Control Specification
COMPONENT DESCRIPTION
Blower Motor Resistor
The blower motor resistor is located on the cooling unit. The blower
motor resistor grounds the blower motor through a series of 1, 2, or
three resistors, depending upon speed selected. For high speed
operation the blower motor resistor is circumvented and the blower
motor grounds directly.
NOTE:
This illustration is for LHD models.
The layout for RHD models is symmetrically opposite.
MJIB0324E
WJIA0441E
MJIB0195E

MTC-86
TROUBLE DIAGNOSIS
Insufficient Cooling
EJS005GM
SYMPTOM: Insufficient cooling
INSPECTION FLOW
*1 .MTC-53, "Operational Check".*2MTC-51, "A/C System Self-diagno-
sis Function".*3MTC-52, "
SELF-DIAGNOSIS CODE
CHART".
*4EC-132, "
Description".*5MTC-4, "Contaminated Refrigerant".*6 .MTC-87, "PERFORMANCE TEST
DIAGNOSES"
*7MTC-89, "Test Reading"*8EM-12, "Checking Drive Belts"
MJIB0244E

MTC-90
TROUBLE DIAGNOSIS
TROUBLE DIAGNOSES FOR UNUSUAL PRESSURE
Whenever system¢s high and/or low side pressure is unusual, diagnose using a manifold gauge. The marker
above the gauge scale in the following tables indicates the standard (usual) pressure range. Since the stan-
dard (usual) pressure, however, differs from vehicle to vehicle, refer to above table (Ambient air temperature-
to-operating pressure table).
Both High- and Low-pressure Sides are Too High
High-pressure Side is Too High and Low-pressure Side is Too Low
Gauge indication Refrigerant cycle Probable cause Corrective action
Both high- and low-pressure sides
are too high.Pressure 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 cooling fan is
insufficient.Insufficient condenser cooling
performance
¯
1. Condenser fins are clogged.
2. Improper 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
kg/cm
2,28psi).Itthen
decreases gradually there-
after.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 engine cool-
ing system.
lAn area of the low-pres-
sure 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
littlecomparedwiththe
specification.
¯
Improper expansion valve
adjustmentReplace expansion valve.
AC359A
Gauge indication Refrigerant cycle Probable cause Corrective action
High-pressure side is too high and
low-pressure side is too low.
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.
AC360A

MTC-92
TROUBLE DIAGNOSIS
Low-pressure Side Sometimes Becomes Negative
Low-pressure Side Becomes Negative
Gauge indication Refrigerant cycle Probable cause Corrective action
Low-pressure side sometimes
becomes negative.
lAir conditioning system
does not function and does
not cyclically cool the com-
partment air.
lThe system constantly func-
tions for a certain period of
time after compressor is
stopped and restarted.Refrigerant does not dis-
charge cyclically.
¯
Moisture is frozen at expan-
sion valve outlet and inlet.
¯
Water is mixed with refriger-
ant.
lDrain water from refrigerant
or replace refrigerant.
lReplace liquid tank.
AC354A
Gauge indication Refrigerant cycle Probable cause Corrective action
Low-pressure side becomes nega-
tive.
Liquid tank or front/rear side of
expansion valve¢spipeis
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 until
no frost is present. Start it
again to check whether or not
the malfunction is caused by
waterorforeignparticles.
lIf water is the cause, initially
cooling is okay. Then the
water freezes causing a
blockage. Drain water from
refrigerant or replace refrig-
erant.
lIf due to foreign particles,
remove expansion valve
and remove the particles
with dry and compressed air
(not shop air).
lIf either of the above meth-
ods cannot correct the mal-
function, replace expansion
valve.
lReplace liquid tank.
lCheck lubricant for contami-
nation.
AC362A

TROUBLE DIAGNOSIS
MTC-95
C
D
E
F
G
H
I
K
L
MA
B
MTC
Self-diagnosisEJS005GP
SYMPTOM: Self-diagnosis cannot be performed (Vehicles equipped with NAVI only).
INSPECTION FLOW
Intake Sensor CircuitEJS005GR
COMPONENT DESCRIPTION
Intake Sensor
The intake sensor is located on the heater & cooling unit. It converts
temperature of air after it passes through the evaporator into a resis-
tance value which is then input to the front air control.
NOTE:
This illustration is for LHD models.
The layout for RHD models is symmetrically opposite.
*1MTC-122, "REMOVAL".*2MTC-122, "INSTALLATION".*3MTC-24, "Maintenance of Lubricant
Quantity in Compressor".
*4MTC-53, "
Operational Check".*5EM-12, "DRIVE BELTS".
*1MTC-55, "
Power Supply and Ground
Circuit for Front Air Control".2.MTC-63, "
Air Mix Door Motor Cir-
cuit".3.MTC-53, "
Operational Check".
MJIB0246E
MJIB0198E

INTAKE SENSOR
MTC-99
C
D
E
F
G
H
I
K
L
MA
B
MTC
INTAKE SENSORPFP:27723
Removal and InstallationEJS005GT
REMOVAL
1. Remove the instrument panel. Refer toIP-10, "Removal and Installation".
2. Disconnect the intake sensor electrical connector.
NOTE:
The intake sensor is located on the top of the heater and cooling
unit assembly next to the A/C evaporator cover.
3. Twist the intake sensor to remove the intake sensor from the
heater and cooling unit assembly.
INSTALLATION
Installation is in the reverse order of removal.
MJIB0325E

MTC-100
BLOWER MOTOR
BLOWER MOTOR
PFP:27226
ComponentsEJS005GU
Removal and InstallationEJS005GV
REMOVAL
1. Remove the glove box assembly. Refer toIP-15, "LOWER INSTRUMENT PANEL RH AND GLOVE BOX"
.
2. Disconnect the blower motor electrical connector.
3. Remove the three screws and remove the blower motor.
INSTALLATION
Installation is in the reverse order of removal.
1. Heater and cooling unit assembly 2. Blower motor 3. Blower motor resistor
MJIB0247E

AIR CONDITIONER FILTER
MTC-101
C
D
E
F
G
H
I
K
L
MA
B
MTC
AIR CONDITIONER FILTERPFP:27277
Removal and InstallationEJS005GW
FUNCTION
The air inside the passenger compartment is filtered by the air condi-
tioner filters when the heater or A/C controls are set on either the
recirculation or fresh mode. The two air conditioner filters are located
in the heater and cooling unit assembly.
REPLACEMENT TIMING
Replacement of the two air conditioner filters is recommended on a regular interval depending on the driving
conditions. Refer toMA-8, "
PERIODIC MAINTENANCE". It may also be necessary to replace the two air con-
ditioner filters as part of a component replacement if the air conditioner filters are damaged.
REPLACEMENT PROCEDURE
1. Remove the glove box assembly.
a. Remove the two lower glove box screws.
b. Open the glove box, then remove the four upper glove box
screws.
NOTE:
It is not necessary to remove the two glove box striker screws.
c. Remove the glove box assembly from the instrument panel to
access the air conditioner filter cover.
2. Remove the screw and remove the air conditioner filter cover.
3. Remove the air conditioner filters from the heater and cooling
unit assembly housing.
MJIB0215E
LJIA0146E
WJIA0628E
MJIB0216E

MTC-102
AIR CONDITIONER FILTER
4. Insert the first new air conditioner filter into the heater and cool-
ing unit assembly housing and slide it over to the right. Insert the
second new air conditioner filter into the heater and cooling unit
assembly housing.
NOTE:
The air conditioner filters are marked with air flow arrows. The
end of the microfilter with the arrow should face the rear of the
vehicle. The arrows should point downward.
5. Install the air conditioner filter cover.
6. Install the glove box assembly in reverse order of removal.
LJIA0148E
MJIB0216E
Lower glove box screws : 3.5 N·m (0.36 kg-m, 31 in-lb)
Upper glove box screws : 3.5 N·m (0.36 kg-m, 31 in-lb)

HEATER & COOLING UNIT ASSEMBLY
MTC-103
C
D
E
F
G
H
I
K
L
MA
B
MTC
HEATER & COOLING UNIT ASSEMBLYPFP:27110
ComponentsEJS005GX
Heater and Cooling Unit Assembly —LHD Models—
MJIB0278E
1. High-pressure A/C pipe 2. Low-pressure A/C pipe 3. Expansion valve
4. Heater core and evaporator pipes
grommet5. A/C drain hose grommet 6. A/C drain hose
7. Heater core pipes 8. Coolant reservoir hose 9. Heater and cooling unit assembly