air condition NISSAN PULSAR 1987 User Guide

46 Engine
(1) Ensure that all carbon and old gasket mate-
rial is cleaned from the manifold and cylinder head
faces. (2) Check the face of the manifold for distortion
using a straight edge and a feeler gauge. (3) Use a new gasket and ensure that the mani-
fold retaining nuts are tightened to the specified
torque in a spiral pattern from the centre outwards. (4) Adjust the throttle cabl e as described in the
Fuel and Engine Management section and the kick-
down cable as described in the Automatic Transaxle
section.
(5) Start the engine and check for air, fuel and
water leaks.
EXHAUST MANIFOLD

To Remove and Install
(1) Bring the engine to operating temperature
and remove the oxygen sensor.
(2) Disconnect the negative battery terminal.
(3) On 1.6 liter models, remove the air cleaner
nuts, disconnect the vacuum hose and withdraw the
air cleaner from the vehicle. (4) Remove the front exhaust pipe flange mount-
ing nuts and separate the exhaust pipe from the
manifold. (5) Remove the heat shield retaining bolts and
withdraw the heat shield from the exhaust manifold. (6) Remove the exhaust manifold to cylinder
head retaining nuts and remove the manifold from the
engine. Discard the manifold gasket. Installation is a reversal of the removal procedure
with attention to the following points:

(1) Ensure that all carbon is cleaned from the
manifold and cylinder head mating surfaces. (2) Check the face of the manifold for distortion
using a straight edge and feeler gauges. (3) Use new gaskets on assembly.
(4) Tighten the exhaust manifold retaining nuts
to the specified torque in the sequence shown in the
illustration. (5) Install the oxygen sensor. Refer to the Fuel
and Engine Management section. (6) Coat the threads of the front exhaust pipe to
manifold retaining nuts with an anti-seize solution
and tighten the nuts to the specified torque.
5. CAMSHAFT DRIVE BELT
Special Equipment Required:
To Adjust — Drive belt adjusting tool
TO REMOVE
(1) Disconnect the negative battery terminal.
(2) Raise the front of the vehicle, support it on
chassis stands and remove the right hand front wheel.
Refer to the Wheels and Tires section. (3) Remove the fasteners securing the engine
splash guard to the right hand front inner mudguard
and remove the splash guard. (4) Loosen the alternator adjusting bolt and if
equipped, the power steering and air conditioning
adjusting bolts. Remove the drive belt(s).


View of the exhaust manifold and components showing
the correct tightening sequence.

View of the 1.8 liter engine with the upper timing belt
cover removed showing the camshaft gear timing
marks. Inset shows the crankshaft pulley timing
marks.

48 Engine

TO INSTAL
(1) Check that the camshaft and crankshaft
timing gears have not been moved and that the timing
marks are still aligned. It will be necessary to tempo-
rarily install the crankshaft pulley to check that the
timing marks are still aligned. (2) Install the drive belt to the crankshaft timing
gear around the water pump gear and onto the
camshaft timing gear.
NOTE: If the original drive belt is being
installed, ensure that the arrow marked on
the belt prior to removal is pointing in the
direction of rotation.

(3) Use the adjusting tool to turn the water
pump assembly sufficiently to engage the water pump
pulley with the drive belt. (4) Install the inner cover lower retaining bolt.
(5) Ensure that the drive be lt is correctly meshed
with the teeth of the camshaft, crankshaft and water
pump gears. Install the crankshaft pulley and tighten
the bolts to Specifications. (6) Adjust the drive belt as described under the
following heading.
(7) Install the drive belt outer cover and fasten
the retaining clips. (8) Install and adjust the alternator and if
equipped, the power steeri ng and air conditioning
drive belts as desc ribed in the Engine Tune-up section.
TO ADJUST

(1) Remove the alternator drive belt and if
equipped, the power steering and air conditioning
drive belts. (2) Release the clips securing the camshaft drive
belt outer cover to the inner cover and remove the
outer cover. (3) Turn the engine in the direction of rotation
until the timing marks on the camshaft and the inner
cover are aligned. (4) Loosen the water pump retaining bolts and
using the adjusting tool, rotate the water pump
housing to gain the required belt tension. The belt is
correctly tensioned when it can be grasped between
the thumb and forefinger midway between the cam-
shaft timing gear and the water pump gear and turned
ninety degrees from i t s operating position.
After the belt has been tensioned, tighten the
water pump retaining bolts to the specified torque.

NOTE: Over tensioning of the drive belt will
result in noisy operation and premature
wear of the belt.

(6) Install the outer drive belt cover.
(7) Install and adjust the alternator, and if
equipped, the power steering and air conditioning
drive belts as desc ribed in the Engine Tune-up section. 6. CAMSHAFT. ROCKER ARMS AND TAPPETS

Special Equipment Required:
To Check Camshaft — Dial gauge, Vee blocks and
micrometers
To Install — Drive belt adjusting tool
It is recommended that a new cylinder head
gasket is installed and the cylinder head bolts renewed
when the camshaft housing is removed.

TO REMOVE
(1) Disconnect the negative battery terminal.
Remove the nuts securing the earth wires to the
cylinder head bolts and remove the earth wires.
(2) On 1.6 liter models, remove the air cleaner
wingnuts and withdraw the air cleaner.
(3) Disconnect the engine breather hoses from
the camshaft housing and the camshaft housing top
cover. (4) Remove the camshaft housing top cover
retaining bolts and remove the top cover. Discard the
gasket.
(5) Remove the camshaft dr ive belt as described
under the previous heading. (6) Using an open ended spanner, hold the
camshaft between the inle t and exhaust lobes of
number four cylinder and remove the camshaft timing
gear retaining bolt and the camshaft timing gear.
(7) Remove the distributor, distributor cap and
high tension leads. If necessary refer to the Fuel and
Engine Management section. (8) Check the camshaft end float before remov-
ing the camshaft from the engine. Mount a dial gauge
to the cylinder block with the plunger bearing on the
distributor drive end of the camshaft. (9) Lever the camshaft towards the dial gauge
and zero the gauge. Move the camshaft in the opposite
direction away from the dial gauge and note the
reading obtained. Check this measurement against
Specifications.

Checking the camshaft end float.

58 Engine

TO INSPECT PISTONS AND CONNECTING
RODS
(1) Remove all carbon deposits from the bottom
of the ring grooves with a ring groove cleaning tool or
a broken ring. Use caution to avoid scoring the
bottom and sides of the ring groove.

NOTE; An ideal method of removing carbon
deposits from pistons is to immerse the
piston in a tank of chemical cleaner. After
soaking, the carbon can be readily hosed off
with water. This method minimizes the
chance of damage through scraping, particu-
larly with aluminum alloy components.

(2) Inspect the pistons for sc uff marks, scoring or
burning. (3) Inspect the ring grooves of the pistons for
excessive wear. Using a new piston ring, check the
clearances between the side of the ring and the ring
lands of the piston with feeler gauges. Compare the
side clearance with the Specifications. (4) Inspect each pair of bearing shells for wear
especially on an outer edge. If one or more pairs of
bearing shells are worn on the outer edge it is possible
that the connecting rod is bent. (5) Before renewing a piston or connecting rod,
inspect the cylinder block to see if it requires reboring
or honing.
If the cylinder block requires reboring, new over-
size pistons will have to be installed.

(6) If a piston or connecting rod is to be
renewed, a special tool wi ll be required to press the
gudgeon pin from the connecting rod. To install the
piston and gudgeon pin to the connecting rod, the
gudgeon pin boss must be accurately heated to 280
degrees C before the gudgeon pin can be inserted in
the little end of the connecting rod.


Replacement connecting rods are supplied only at
their highest production weight and must be matched
to the weight of the remaining connecting rods by
filing the big end boss. For these reasons it is
recommended that the work be entrusted to a repu-
table engine reconditioner w ho will have the special-
ised equipment and knowledge to carry out this work.

TO INSPECT CYLINDER BLOCK AND BORES
With the pistons removed as previously de-
scribed, carry out the following checks and measuring
procedures:

(1) Check the cylinder bores for cracks, scores or
scuffs.


Check for cylinder bore wear. Difference between A
and B measurement at top of piston travel is out of
round dimension. Difference between A at top and at
bottom of piston travel is cylinder taper.

(2) Using an accurate cylinder gauge, measure
each cylinder bore for wear. Take the measurements,
at the upper and lower sections of the bore in two
directions — along and across the cylinder block.
Refer to the illustration.
(3) If the wear in any cylinder exceeds the
specified limit, rebore and hone all the cylinders to the
nearest oversize for pistons and rings. (4) With a straight edge and feeler gauge, check
the top face of the cylinder block for distortion, using
the same procedure described for the cylinder head.
STRAIGHT EDGE
Measuring the piston ring side clearance.
Checking the cylinder block face for distortion.

Engine 59
(5) If the engine is completely dismantled, thor-
oughly clean the cylinder block with solvent and
compressed air paying particular attention to the
oilways. Inspect the block for cracks and damage.

TO CHECK PISTON CLEARANCE
(1) Using an accurate cylinder measuring gauge,
measure and note the diameter of each bore as
previously described. (2) Measure each piston skirt using a microme-
ter as follows:
(a) On 1.6 liter models, measure each piston
skirt at a point 9 mm above the bottom skirt edge and
at right angles to the gudgeon pin axis. (b) On 1.8 liter models, measure each piston
skirt at a point 6 mm above the bottom skirt edge and
at right angles to the gudgeon pin axis.
(3) The difference between the bore and the
piston measurement is the piston clearance. If the
clearance exceeds the Specifications, renew the pistons
and rebore all the cylinders.
(4) Cylinders that have had new pistons installed
or that have been rebored should have the piston
clearance checked again.

and not engine or transmission oil, mineral spirits or
kerosene.

(2) Honing should be carried out by moving the
hone up and down fast enough to obtain a cross hatch
pattern. When hone marks intersect at 60 degrees, the
pattern is most satisfactory for correct seating of rings.
(3) After honing it is necessary that the block be
cleaned again to remove all traces of abrasives.
NOTE: When deglazing, the cylinder should
be honed only sufficiently to eliminate the
glazed condition. Excessive honing will in-
crease the bore size and alter the piston
clearance.

(4) When honing is complete, ensure that the
cylinder bore, crankcase area and oilways are thor-
oughly cleaned. (5) After the cylinder block has been cleaned and
dried, wipe the bores with a lint free cloth and smear
them with engine oil to prevent rusting.
NOTE: All abrasives must be removed from
the engine components after honing. A so-
lution of soap and water should be used with
a brush and the components thoroughly
dried. A bore can be considered clean when
it can be wiped clean with a white cloth and
the cloth remains clean. Oil the bores after
cleaning to prevent rusting.

TO FIT NEW PISTON RINGS AND INSTAL
PISTONS

Once the correct piston and the bore relationship
has been determined and the pistons cleaned or
renewed as necessary, proceed as follows:

(1) Place a ring into number one cylinder bore
and using an inverted piston push the ring down 50
mm into the cylinder bore. (2) Withdraw the piston and measure the gap in
the ring with feeler gauges. Adjust the end gap of the
ring by filing as necessary. See the Specifications for
the ring end gap.
Measuring the piston diameter using a micrometer. On
1.6 liter models, dimension A = 9 mm. On 1.8 liter
models, dimension A - 6 mm.
TO INSPECT AND DEGLAZE CYLINDER
BORES

Cylinder bores that are fit for further service with
the original pistons, but require re-ringing, should be
deglazed with a hone. Before honing the cylinder
bores with crankshaft insta lled, place plenty of clean
rag over the crankshaft to keep the abrasive materials
from entering the crankcase area.

(1) Deglaze the cylinder walls using a cylinder
surfacing hone equipped with suitable stones. Inspect
the cylinder walls after each 20 strokes. Use honing oil
Checking the piston ring end gap.

Cooling and Heating Systems 69

the cylinder head or cylinder block and renew the
cylinder head gasket.

(2) Crack in the cylinder head or cylinder block:
Repair or renew as necessary.

NOTE; Check the engine for internal leak-
age by withdrawing the dipstick and inspect-
ing for emulsified oil. Run the engine and
check for excessive steam at the exhaust
pipe which would indi cate coolant leakage
into the combustion chamber.

COOLANT LOSS BY OVERFLOW
(1) Overfull system: Drain the excess coolant
from the system.
(2) Faulty radiator cap: Renew the faulty cap.
(3) Blocked radiator core tubes: Clean or renew
the radiator core.

(4) Faulty thermostat: Renew the thermostat.
(5) Coolant foaming due to poor quality anti-
freeze or corrosion inhibitor: Drain the system and
renew the coolant and additive.

Renew the radiator cap if the sealing rubber has
deteriorated.
ENGINE OVERHEATING
(1) Radiator cap defective: Renew the radiator
cap.
(2) Incorrect fuel mixture: Check the fuel system
as described in the Fuel and Engine Management
section. (3) Obstructed air passage through the radiator
core from the front to the rear: Blow the obstruction
from the rear to the front of the radiator core using
compressed air or water pressure. (4) Faulty thermostat: Renew the thermostat.
(5) Incorrect ignition timing: Check and adjust
the ignition timing as described in the Engine Tune-up
section. (6) Incorrect valve timing: Set the valve timing
as described in th e Engine section.
(7) Loss of coolant from the overflow: Check
and rectify as described under the heading Coolant
Loss By Overflow.
(8) Poor circulation: Check and rectify as de-
scribed under the heading Coolant Circulation Faulty.
(9) Low engine oil level: Stop the engine imme-
diately and replenish the oil in the sump. (10) Restricted muffler, catalytic converter or
damaged tailpipe, accompanied by loss of power:
Remove the restrictions or renew the faulty com-
ponents as necessary.
(11) Incorrectly adjusted or dragging brakes:
Check and rectify by adjustment or renewal of
components. (12) Faulty temperature gauge and/or sender unit:
Check and rectify as necessary.
NOTE: Engine overheating is indicated by
an excessive rise in engine temperature
shown by the temperature gauge.

Overheating is usually accompanied by
steam emitting from the coolant overflow
pipe and loss of engine power. A blown
cylinder head gasket may be indicated by
bubbles in the coolant.

COOLANT CIRCULATION FAULTY
(1) Partial blockage of the radiator core tubes:
reverse flush or renew the radiator core.
(2) Sludge deposits in the engine water jacket:
Clean and flush the engine water jacket and add
inhibitor to the coolant. (3) Faulty water pump: Renew the water pump.
(4) Faulty thermostat: Renew the thermostat.
(5) Collapsing lower radiator hose: Renew the
lower radiator hose and check the radiator core tubes. (6) Insufficient coolant in the system: Replenish
the coolant and check for leaks.
NOTE: If rust or sludge deposits are sus-
pected, check the color of the coolant in the
radiator. Rusty or muddy coolant indicates
rust or sludge in the system.

2. HEATER AND AIR CONDITIONER TROUBLE SHOOTING

NO HOT AIR INSIDE VEHICLE
Faulty thermostat: Renew the thermostat.
Faulty heater valve: Check and renew the

Blocked heater hoses: Remove the blockage.
Blocked heater core: Clean or renew the core.

NOTE: Ensure that the engine is reaching
normal operating temperature. If in doubt
check the operation of the thermostat as
described under the Thermostat heading in
this section.

(1)
(2)
valve.
(3)
(4)

70 Cooling and Heating Systems


Installed view of the heater hoses. 1.6 liter models with the air cleaner removed for clarity
.
When the engine is at normal operating
temperature and the heater valve is open,
both of the heater hoses should feel
warm/hot. If the valve is not allowing the
coolant to flow, one hose will be hot while
the other will be cold.

NO COOLED AIR INSIDE VEHICLE
(1) Compressor drive belt slipping or broken:
Renew and/or adjust the drive belt as described in the
Engine Tune-up section.
(2) Insufficient refrigerant: Check the system for
leaks and charge as necessary. Refer to the Air
Conditioning heading in th is section for information
on checking the refrigerant level. (3) Compressor inoperative: Check for power to
the compressor clutch before removing the compres-
sor for repair by a specialist. (4) Heater system allowing warm air to mix with
cooled air: Check the operation of the heater system.
NOTE: The above trouble shooting proce-
dures are basic checks only. If the air
conditioning system is suspect, it is rec-
ommended that the vehicle be taken to an
authorized dealer for testing and repair.
It is normal for water to be seen drain-
ing under the vehicle from the evaporator
after the vehicle has been operated with
the air conditioning on.

3. DESCRIPTION
The cooling system is of the sealed, pressurized
type with fan and water pump assistance. The system
is pressurized in order to raise the boiling point of the
coolant and so increase the efficiency of the engine.

Provision for pressure a nd vacuum relief of the
system is incorporated in the radiator cap.

The radiator overflow hose is connected to a
reserve tank mounted adjacent to the battery. As the
coolant volume expands due to an increase in tem-
perature, the pressure valve in the radiator cap opens
and allows the excess coolant to flow into the reserve
tank. When the engine is stopped and the temperature
of the coolant falls, the vacuum valve in the radiator
cap opens and allows the excess coolant in the reserve
tank to siphon back into the radiator. Thus the
necessity for frequent topping up of the coolant is
eliminated.

The temperature of the cooling system is con-
trolled by a thermostat located in the thermostat
housing attached to the cylinder head.

The thermostat prevents circulation of coolant
through the radiator by directing coolant through the
by-pass circuit, until the engine has reached operating
temperature. This restricted circulation allows the
engine to reach operating temperature quickly, im-
proving drivability and fuel economy.

Removal of the thermostat to cure overheating is
not recommended because th e by-pass circuit will
remain open reducing the amount of water flowing
through the radiator.

An anti-corrosion inhibitor should always be
added to the coolant to protect the cooling and
heating systems from corrosion.

The water pump is mounted to the front of the
engine and is driven by the camshaft drive belt. It is
equipped with a double row ball bearing and a spring
loaded seal assembly. The water pump is a disposable
unit and cannot be repaired.

The fan is driven by an electric motor which is
actuated by the coolant temperature sensor and the
control unit.

On vehicles equipped with air conditioning, an
additional electric fan is m ounted to the radiator. This
fan is controlled by a sw itch connected to the air
conditioning compressor.

The radiator consists of an aluminum core with
plastic side tanks. Minor damage to the core can be
repaired using Nissan repair agent.

The left hand tank of the radiator houses the
transaxle oil cooler on automatic transaxle models.

To drain the cooling system a drain plug is
provided on the lower radiator pipe outlet.

4. RADIATOR
NOTE: To avoid scalding, use caution when
releasing the radiator cap on an engine
which is at the normal operating tempera-
ture. Turn the cap anti-clockwise to the first
stop and allow any pressure in the system to
release. When the pressure is released turn
the cap past the stop and remove it from the
radiator.

Cooling and Heating Systems 71

TO DRAIN AND REFILL
(1) Place a drain tin under the radiator drain
plug.
(2) Switch the heater controls to the maximum
heat position. (3) Remove the radiator cap and open the
radiator drain plug.
(4) Disconnect the reserve tank hose from the
radiator filler neck. (5) Lower the end of the hose and drain the
coolant from the reserve tank. (6) After all the coolant has drained from the
cooling system, install the radiator drain plug
ensuring
that the plug seal is in good condition. (7) Disconnect the wire from the temperature
sender switch and remove the switch using a suitable
spanner.
(8) Using a clean container, mix Nissan long life
coolant with clean soft water to the proportions
stipulated on the coolant container.
(9) Slowly pour the premixed coolant into the
radiator until the radiator is full and all air has
escaped through the temperat ure sender switch hole.
Install the radiator cap. (10) Fill the coolant reserve tank to the Maxi-
mum mark.
(11) Start the engine and allow it to idle.
(12) When coolant starts to flow through the
temperature sender switch hole, install the temperature
sender switch and tighten securely. (13) Continue idling the engine until the cooling
fan is activated.
(14) Switch the engine off and allow it to cool.
(15) Refill the radiator using coolant and install
the radiator cap.

Dismantled view of the radiator and associated components. Automatic transaxle model with
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.