1987 NISSAN PULSAR air conditioning

72 Cooling and Heating Systems

(16) After the vehicle has been driven several
kilometers check the coolant level in the reserve tank
and top up if necessary.

TO REMOVE
(1) Drain the cooling system as previously de-
scribed.
(2) Loosen the hose clamps and disconnect the
hoses from the radiator. (3) If applicable disconnect the automatic trans-
axle oil cooler hoses from the left hand side radiator
tank. Plug the hoses and fitt ings to prevent the entry
of dirt and the loss of fluid.
(4) Disconnect the hose from the reserve tank at
the top of the radiator. (5) On models with air conditioning, remove the
hoses and support bracket bolts and move the bracket
and hoses away from the top of the radiator. (6) Remove the radiator support bracket bolts
from the radiator support pa nel and lift the radiator
from the lower mountings and out of the vehicle.
NOTE: A radiator that has been in use for
some time should not be allowed to stand
empty for any length of time. The radiator
should be immersed in a tank of coolant or
otherwise kept full. If applicable, ensure that
no coolant is allowed to enter the automatic
transaxle oil cooler in the left hand side tank
of the radiator.

Failure to observe this precaution may
result in overheating when the engine is put
back into service. This is caused by internal
deposits in the radiator drying and flaking
and so obstructing the circulation of the
coolant in the system.

TO FLUSH AND CLEAN
(1) Remove the radiator as previously described.
(2) Apply a water hose to the radiator outlet and
reverse flush the radiator until the water flowing from
it is clean.

Cleaning the radiator core from the rear to the front
using a garden hose.
(3) Stand the radiator upright and apply a
stream of water or compressed air to the radiator core
from the rear to [he front. Maintain this procedure
until all dirt and foreign matter is removed from the
radiator core.
(4) With the aid of a light, make a visual check
of the core tubes through the radiator inlet or outlet
fittings. If it is apparent that the tubes are severely
impregnated with flakes of rust it will be necessary to
renew the radiator assembly.
TO REPAIR

The repair procedure described below is only
suitable for holes occurring in the radiator core tubes
that are not bigger than approximately 1 mm.

(1) Suitably mark the area of the leak using a
piece of chalk or similar. (2) Remove the radiator from the vehicle as
previously described, clean it thoroughly and dry the
damaged area with a hair dryer. (3) If necessary, carefully cut away or bend the
fins from the tubes to expose the affected area.
NOTE: Do not remove more than 25 mm
total finning from the radiator or cooling
performance will be affected.

(4) Clean the damaged area carefully using a
scraper and wipe clean using a cloth moistened with
petrol.
(5) Apply well mixed Nissan or Holden adhe-
sive part number 21411-J7025, or equivalent, spar-
ingly to the damaged area using a wooden spatula.
(6) Allow the repair to dry in ambient condi-
tions for a minimum of 3 hours before installing the
radiator to the vehicle and testing for leaks. Do not
use heat to promote drying.
TO INSTAL

Installation is a reversal of the removal procedure
with attention to the following points:
Reverse flushing the radiator using water pressure.

Cooling and Heating Systems 73
(1) Renew all hoses that show signs of cracking
or perishing.
(2) Before finally tightening the hose clips, en-
sure that the hoses are push ed fully onto the radiator
and are not kinked. (3) On automatic transaxle models, ensure that
the oil cooler hoses are correctly installed to the
radiator and show no signs of leakage. Check and top
up the automatic transaxle fluid as necessary.
5. COOLING FAN
The radiator cooling fan is controlled by the
electronic control unit, and on vehicles with air
conditioning, the condenser fan relay. On vehicles
with air conditioning there are two cooling fans, one
is larger than the other. The large fan is for the
radiator and the smaller fan provides extra cooling
when the air conditioning is activated. Each fan is
controlled by a separate system.

TO TEST COOLING FAN AND SYSTEM
(1) With the cooling system cold and the air
conditioning, if applicable, switched off, switch the
ignition On and confirm that the cooling fan is
stationary.

NOTE: Leave the ignition On for all tests
unless otherwise stated.

(2) In the above test, if the cooling fan rotates,
proceed as follows:

(a) Disconnect the cooling fan relay from the
rear of the engine compartment relay box.
(b) If the fan stops, backprobe terminal C1 at
the electronic control unit using an LED test lamp
connected to the positive battery terminal. If no
circuit exists, renew the cooling fan relay.

View showing the location of the diagnostic link
connector. Passengers seat removed for clarity.
If a circuit exists, check the wiring harness
between the electronic control unit and the relay for
short circuits to earth and repair if necessary. If no
short circuit is present renew the electronic control
unit.


Schematic layout of the cooling fan, coolant temper-
ature sensor and related electrical components.

Installed view of the engine compartment relays. KEY

1. To Battery
2. Fusible link
COLOUR CODE
3. Fusible link
B-Black
4. Fusible linkL- Blue
5. I
gnition relayY- Yellow
6. Fuse 20 am
pW-White
7. Coolin
g fan relayO-Orange
8. Coolin
g fan
9. Coolant tem
perature
sensor
10. To air conditionin
g
fan rela
y
11. To throttle
position
sensor
12. Control unit

74 Cooling and Heating Systems
NOTE: Refer to the Fuel and Engine Man-
agement section for the correct procedure for
backprobing the control unit.

(3) In operation (1) if the cooling fan is station-
ary proceed as follows:

(a) Connect a jumper lead between the terminals
A and B of the diagnostic link connector. (b) if the fan runs, the fan circuit is satisfactory.
If the engine is overheating check the coolant temper-
ature sensor as described in the Fuel and Engine
Management section under the appropriate codes. (c) If the fan does not run, check the fuse (6) and
the fusible link (4) show n on the illustration.
(d) Backprobe terminal C1 at the electronic
control unit using an LED t est lamp connected to the
positive battery terminal. If no circuit exists, renew
the electronic control unit. (e) If the fuse and fusible links are serviceable,
ensure that power is available at the white and pink
wires from the fuse and fusible link of the cooling fan
relay. Repair any faults in the wiring to that point if
necessary. (f) Switch the ignition Off. disconnect the
cooling fan wiring connector at the radiator and
connect power to the fan. Renew the fan if it does not
run.

(4) On air conditioned models, remove the
jumper lead from the ALDL connector if still in-
stalled, start the engine and allow it to idle. Switch the
air conditioning on and ensu re that the cooling fan
runs.

If the cooling fan is opera ting as described above
but cooling system problems still exist, refer to the
Trouble Shooting heading at the start of this section.

TO REMOVE AND INSTAL COOLING FAN
(1) Disconnect the negative battery terminal.
(2) Disconnect the cooling fa n and, if applicable,
the air conditioning fan wiring connectors at the
upper edge of the radiator. (3) On models with air conditioning, remove the
compressor hose bracket bolt from the centre of the
radiator support panel.

Dismantled view of the fans and the shroud assembly. Air conditioned model.

Cooling and Heating Systems 75
(4) Remove the bolts retaining the fan shroud
assembly to the radiator and carefully move the
shroud assembly upwards and towards the engine to
release it from the lower mountings.

NOTE: On models with air conditioning, it
will be necessary to hold the air conditioning
compressor hoses toward s the engine to
allow clearance for removal of the shroud
assembly.

(5) If necessary, remove the fan from the fan
motor by removing the retaining bolts or on some
models the nut and washers.
(6) If necessary, remove the fan motor from the
shroud assembly by removing the retaining bolts or
nuts. Installation is a reversal of the removal procedure
with attention to the following points:

(1) Ensure all the fan motor and fan retaining
nuts and bolts are tightened securely. (2) Ensure that all the rubber mountings are in
good condition. Installation is a reversal of the removal procedure
with attention to the following points:

(1) Ensure that all sealing surfaces are clean.
(2) Renew the O ring on installation.
(3) Tighten the thermostat cover retaining bolts
securely.
(4) Fill the cooling system as previously de-
scribed ensuring that the heater control lever is in the
maximum heat position. Check for coolant leaks.
TO CHECK

NOTE: A visual examination of the thermo-
stat will often determine its serviceability
and make further testing unnecessary. For
instance, a thermostat with its valve fully-
open when removed from a cold engine is
obviously faulty and should be renewed.

Remove the thermostat from the thermostat
6. THERMOSTAT
Special Equipment Required:
To Check — Thermometer

TO REMOVE AND INSTAL
(1) Drain the cooling system as previously de-
scribed under the Radiator heading.
(2) On 1.6 liter models, remove the air cleaner
assembly. Refer to the Fuel and Engine Management
section if necessary. (3) Disconnect the top radiator hose from the
thermostat cover.
(4) Remove the bolts retaining the thermostat
cover to the thermostat housing. (5) Remove the thermostat cover, thermostat
and O ring from the thermostat housing.
NOTE: The thermostat and cover are ser-
viced as a unit and cannot be renewed
separately.


View of the thermostat removed from the vehicle and dismantled for testing. Line drawing showing the correct method to test the
thermostat.

(4) Progressively heat the mixture noting the
temperature reading on the thermometer as the ther-
mostat valve commences to open and when it is fully
open.

See the Specifications for opening and fully open
temperatures.

A thermostat which is not opening or is not open
at the specified temperatures should be renewed.

78 Cooling and Heating Systems
The air conditioner operates only when the engine
is running as the compressor is belt driven from the
engine.

Operating the air conditioner with the tempera-
ture control raised to a hot setting will produce
dehumidified hot air which is particularly useful for
demisting the vehicle glass.

Maximum cooling is achieved by operating the air
conditioner with the temperature control lowered
fully to the coldest setting . Operate the fan at high
speed when using the coldest temperature setting to
avoid forming ice on the evaporator.

TO REMOVE AND INSTAL HEATER UNIT
(1) Remove the dashboard as described in the
Body section. (2) Drain the cooling system as previously de-
scribed in this section. (3) Loosen the hose clamps and disconnect the
heater hoses from the heater pipes.
NOTE: If the heater hos es will not come off
the heater pipes, do not use excess force or
the heater core retaining strap will be dam-
aged. Cut the hoses from the heater pipes.

(4) Remove the steering column upper mount-
ing bolts. (5) Remove the steering column cross support
bolts and move the support towards the right hand
side of the vehicle. (6) Remove the centre support retaining bolts
and remove the centre support from the vehicle.
(7) Remove the demister duct and the right
hand side ventilator duct from the vehicle. (8) Disconnect the blower fan wiring connector
from the rear of the heater controls. (9) Remove the heater retaining bolts.
(10) On models with air conditioning, it will be
necessary to loosen the evaporator mounting bolts. (11) Working in the engine compartment, push
the heater pipe grommet through the bulkhead. (12) Maneuver the heater unit upwards slightly
and out from the bulkhead using care not to damage
the heater pipes. (13) To remove the heater core and tap assembly,
remove the screws from the retaining strap and slide
the heater core from the heater unit.
Installation is a reversal of the removal procedure
with attention to the following points:

(1 ) Before installing the heater unit to the

View of the heater unit with the dashboard, centr e support, demister duct and right hand ventilator
duct removed.

Cooling and Heating Systems
11. BLOWER FAN
TO REMOVE AND INSTAL
(1) Disconnect the negative battery terminal.
(2) Working below the glov e compartment, dis-
connect the wiring connector to the blower fan motor.
(3) Remove the bolts retaining the blower fan
motor and carefully lower the motor while disconnect-
ing the drain hose.

Installation is a reversal of the removal procedure
with attention to the following points:
( t ) Tighten all bolts securely.
(2) Check that the blow er fan operates correctly.

Dismantled view of the blower fan and associated
components.
12. AIR CONDITIONING
DESCRIPTION
The air conditioning system, when used in con-
junction with the heater, enables any reasonable tem-
perature to be achieved inside the vehicle. It can also
reduce the humidity of the incoming air, aiding
demisting even when cooling is not required.

The basic components of the air conditioning sys-
tem are an evaporator, co ndenser, compressor, re-
ceiver/dryer, expansion valve and pipes and hoses
carrying the refrigerant through the system. Various
subsidiary controls and sensors are also utilized to
protect the system against low or high pressure and
excessive temperature.

The refrigerant will boil at a very low tempera-
ture (-33 deg C) and therefore must be contained
under pressure. Escaping refrigerant can cause frost-
bite and eye damage and will produce a poisonous gas
when burnt. Also, if the system suffers a rapid loss of
refrigerant, oil from the compressor may be carried
out with the refrigerant. It is recommended that any
work requiring disconnection of the components be
referred to an au thorized dealer.

In the event of major repair s to the vehicle such as
engine removal, the compress or hoses are of sufficient


Schematic diagram of a typical air conditioning
system.
length to allow the compressor to be removed as the
engine is lowered from the engine compartment with-
out disturbing any refrigerant line connections.

If the operation of the air conditioning system is
in doubt, it is recommended that the vehicle be taken
to an authorized dealer for testing and repair.

TO CHECK REFRIGERANT CHARGE
(1) Start the engine and operate the air condi-
tioner on maximum cooling for a few minutes.
(2) Observe the flow of refrigerant through the
sight glass located at the top of the receiver/dryer. On
some models it may be necessary to use a mirror to
see the sight glass. (3) If the system is operating correctly, the sight
glass will be clear during the operation of the com-
pressor. Occasional bubbles may be seen when the
compressor cycles on and off during operation, but a
NUT j-
Bubbles in the sight glass when the air conditioner is
operating indicates a low refrigerant charge.

Cooling and Heating Systems 81
continuous stream of bubbles indicates that the refriger-
ant charge is low.

A large number of bubbles or foam indicates that
the refrigerant charge is very low.

No bubbles or the presen ce of oil streaks in the
sight glass indicate that the system is completely
empty.

NOTE: If the outside air temperature is
high, a certain number of bubbles may be
observed in the sight gl ass, even though the
system is fully charged.

If the system requires recharging, the vehicle
should be taken to an authorized dealer for evacu-
ation, leak testing and recharging.

Do not operate the system if it is known that the
refrigerant charge is low as damage may result.

MAINTENANCE
The air conditioning system requires l i t t l e main-
tenance other than the following. Where applicable,
refer to the Lubrication an d Maintenance section for
the recommended service intervals.

(1) Check the refrigerant charge level in the
receiver/dryer sight glass. Recharge the system as
necessary. It is considered normal for the system to
require periodic recharging. (2) Inspect the air conditioner pipes and hoses
for leaks, deterioration and alignment. Evidence of oil
leakage is an indication of refrigerant leakage. Repair
or renew as necessary.
(3) Inspect the evaporator drain tube and the
condenser cooling fins for blockage. Clean as neces-
sary.
(4) Check the drive belt for deterioration and for
correct tension. Refer to the Engine Tune-up section
for the correct procedure.
(5) Operate the system at least once a week for
approximately 15 minutes to keep the compressor
seals lubricated.

86 Fuel and Engine Management
other. The fuel pressure is maintained at a constant
pressure relevant to the manifold vacuum. A dispos-
able paper element fuel filter is mounted on the engine
bulkhead.

The amount of fuel injected is relevant to the time
the injector remains open. The basic time the injector
remains open is governed by the control unit which
uses information from the various sensors to give
optimum engine efficiency for given conditions.

The idle air control (IAC) valve controls the fast
idle speed during engine warm up and maintains the
basic idle speed at a set value by compensating for
loads such as air conditioning or the selection of Drive
on automatic transaxle models.

The throttle body assembly is mounted to the
inlet manifold and controls the amount of air entering
the engine by the action of the throttle valve.

Efficient operation of the EFI system depends on
accurate signals being receiv ed by the control unit and
controlled air flow beyond the throttle valve. There-
fore it is essential that all air, fuel and electrical
connections be clean and tight.

3. SERVICE PRECAUTIONS AND
PROCEDURES

Electronic ignition systems can produce danger-
ously high voltages in both the primary and secondary
circuits. For this reason, extreme care must be taken
when working on or near the ignition system.

Do not start the engine if the battery terminals are
not clean and tight.

Do not use the fast charge or boost settings on a
battery charger to start the engine.

Do not disconnect the battery terminals while the
engine is running.

Disconnect the battery terminals before charging
the battery.

Disconnect the negative ba ttery terminal before
working on the engine management system.

Do not subject the control unit to temperatures
above 80 deg C.

Ensure that all wiring connectors are clean and
tight.

Disconnect the battery terminals and the control
unit wiring connectors before attempting any welding
operations.

Do not direct a steam cleaning or pressure
washing nozzle at engine management components
when cleaning the engine.

Ensure that the ignition is Off prior to disconnect-
ing the battery terminals, fusible links or the control
unit wiring connectors.

TO CONNECT ELECTRICAL TEST
EQUIPMENT

NOTE: Some types of tachometers, timing
lights and ignition system analysers are not
compatible with this engine management
system and may result in incorrect readings.
It is therefore recommended that the man-
ufacturer of the lest equipment be consulted
before proceeding to use the equipment.

If a test procedure requires the use of a
test lamp or voltmeter, ensure that only the
specified instrument is used to prevent mis-
leading diagnosis.

MULTIMETER
It is essential that in all tests where voltage or
resistance is to be measur ed, a digital display multi-
meter with a minimum 10 megohms impedance be
used.


The correct method of backprobing the wiring connec-
tors. The meter test probe should be modified with a piece of thin wire as shown.
All meter readings are to be performed with the
component wiring connectors installed unless other-
wise instructed. This can be done by inserting the
meter test probes from the wiring harness side of the
connector or backprobing. If the test probes are not
thin, they should be modified by attaching a thin piece
of wire to the end, giving a fine point that will not
damage the connector. Ensure that the wire is making
good contact with the probe.

If sealing plugs or boots are removed from wiring
connectors to facilitate bac kprobing, ensure that they
are correctly installed at the conclusion of the test
procedure.

To identify wiring connector terminals refer to the
wiring circuit diagrams.

Test Lamp
To avoid damage to the electronic components
when testing, the use of an LED (light emitting diode)
test lamp is recommended.