Nissan PULSAR N13 Series / ASTRA LD Series. Instruction — part 18

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 pushed 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 link

L

- Blue

5. Ignition relay

Y

- Yellow

6. Fuse 20 amp

W

- White

7. Cooling fan relay

O

- Orange

8. Cooling fan

9. Coolant temperature

sensor

10. To air conditioning

fan relay

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) shown on the illustration.

(d) 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 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 ensure that the cooling fan
runs.

If the cooling fan is operating 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 fan 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 towards 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.

Cooling and Heating Systems

7. THERMOSTAT HOUSING

Special Equipment Required:

To Adjust Camshaft Drive Belt — Adjusting tool

TO REMOVE AND INSTAL

(1) Disconnect the negative battery terminal.
(2) On 1.6 liter models, remove the air cleaner

assembly from the engine. Refer to the Fuel and
Engine Management section if necessary.

(3) Drain the cooling system as previously de-

scribed.

(4) Remove the camshaft drive belt as described

in the Engine section under the heading Camshaft
Drive Belt.

(5) Remove the bolts retaining the camshaft

drive belt rear cover to the cylinder block and remove
the rear cover.

\ \

COOLANT TEMPERATURE SENSOR

TEMPERATURE SENDER SWITCH

View of the thermostat housing and
components.

(6) Disconnect the top radiator hose, the heater

hose and the inlet manifold heater hose from the
thermostat housing.

(7) Disconnect the wire from the temperature

sender switch and the coolant temperature sensor.

(8) Remove the bolts retaining the thermostat

housing to the cylinder head and remove the thermo-
stat housing and the O ring from the cylinder head.

Installation is a reversal of the removal procedure

with attention to the following points:

(1) Ensure that all mounting faces are clean.
(2) Renew the O ring on installation.

NOTE; Ensure that the O ring is not
twisted. Do not use sealant.

(3) Tighten the thermostat housing retaining

bolts to the specified torque.

(4) Adjust the camshaft drive belt tension as

described in the Engine section under the heading
Camshaft Drive Belt.

(5) Fill the cooling system as previously de-

scribed and check for coolant leaks.

8. WATER PUMP

Special Equipment Required:

To Adjust Camshaft Drive Belt — Adjusting tool

TO REMOVE AND INSTAL

NOTE: The water pump is non-repairable
and if faulty must be renewed as a complete
assembly.

(1) Drain the cooling system as previously de-

scribed.

(2) Remove the camshaft drive belt as described

in the Engine section under the heading Camshaft
Drive Belt.

(3) Remove the water pump retaining bolts and

remove the water pump and the O ring from the
engine.

Installation is a reversal of the removal procedure

with attention to the following points:

View of the water pump and components removed

from the vehicle.

(1) Ensure that all mounting faces are clean.
(2) Use a new O ring and smear it with a liberal

amount of silicone grease.

(3) Install the water pump to the engine but

do
not tighten the retaining bolts until the camshaft drive
belt has been installed and tensioned correctly as
described in the Engine section under the heading
Camshaft Drive Belt.

(4) Fill the cooling system as previously de-

scribed in this section and check for coolant leaks.

9. WELCH PLUGS

To facilitate the casting of the cylinder block and

cylinder head passages and water jackets, a number of
openings had to be made at manufacture.