Nissan PULSAR N13 Series / ASTRA LD Series. Manual — part 19

Cooling and Heating Systems

77

These openings are plugged with welch plugs. The

plugs may have to be renewed when cleaning the
engine water jackets or when defective due to corro-
sion.

TO RENEW

NOTE: If a welch plug is found to be
corroded it is good policy to renew all the
welch plugs.

(1) Drain the radiator and cylinder block.
(2) Remove the necessary engine components or

accessories to gain ample working space around the
welch plug.

(3) Using a punch and hammer, tap the welch

plug on its outer circumference into its opening.

(4) Grasp the edge of the welch plug with a pair

of multi-grip pliers and using the shoulder of the pliers
as a fulcrum, lever the plug out of its opening.

(5) Thoroughly clean and dry the welch plug

opening.

(6) Lightly smear the edge of a new welch plug

and the opening with Loctite 675.

(7) Place the welch plug onto the opening and

using a tube or socket fitting the rim of the plug, drive
the plug squarely into its opening.

NOTE; The welch plug must be driven into
the opening straight and squarely or leaks
may occur.

(8) Install the components which were removed

to gain access to the plug.

(9) Fill the cooling system as previously de-

scribed. With the reserve tank pressure cap installed,
run the engine until it reaches normal operating
temperature and check for coolant leaks.

10. HEATER UNIT, WATER VALVE AND

CONTROLS

DESCRIPTION

The heater controls use four adjustments to direct

air through the vehicle.

The air intake control selects fresh air from

outside the vehicle or recirculates air from inside the
vehicle. The recirculate position is used in dusty
conditions or to rapidly heat or cool the vehicle
interior. The fresh air position is the best to deodorize
the vehicle interior or demist the windscreen.

The air control lever is used to direct air to the

face outlets, the floor outlets and the windscreen
outlets. This control also has two bi-level positions
where air may be directed to the face and floor outlets
or the windscreen and floor outlets.

The temperature control opens or shuts the heater

water valve to control the flow of engine coolant
through the heater core, which raises or lowers the
temperature of the air passing through the core.
Maximum heating is only available when the engine is
at the normal operating temperature.

The fan speed control switches the fan on and off

and is used to select the desired fan speed.

Air conditioned models use identical controls

with the addition of an air conditioner on/off button.
The centre of the button is illuminated when the air
conditioner is switched on.

Tap the welch plug on its outer circumference into the

cylinder block.

Using a correct fitting tube or socket, drive the welch

plug into its opening.

View of the heater controls.

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 hoses 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, centre support, demister duct and right hand ventilator

duct removed.

Cooling and Heating Systems

79

Front view of the heater unit showing the heater

controls.

vehicle adjust the heater water tap control rod as
follows:

(a) Disconnect the control rod from the air mix

door lever.

(b) Pull the control rod until there is a clearance

of approximately 2 mm between the end of the
control rod, which is inside the spring and the top
lever. Hold the rod in this position.

(c) Turn the air mix door lever fully anti-

clockwise and while holding the lever install the
control rod to the air mix door lever.

(d) Ensure that the heater water tap is operating

correctly and shutting off correctly by blowing through
the heater pipes.

NOTE: No access to the heater water tap
control rod is possible once the heater unit is
installed in the vehicle.

(2) When maneuvering the heater unit into

position use care not to damage the heater pipes.

(3) Wet the heater pipe grommets with soapy

water and install onto the heater pipes.

(4) Check the heater controls for correct opera-

tion before installing the dashboard and adjust the
controls if necessary using the procedure that follows.

(5) Operate the heater unit with the engine

running and ensure that the operation is satisfactory
and no leaks are present.

clockwise and install the lower rod then the upper
rod
in that order.

(5) Hold the side link fully clockwise and the

demist door lever fully anti-clockwise and install the
demist door rod.

(6) Holding the side link fully clockwise, set the

air control lever on the dashboard to the face vent
position and install the air control cable to the side
link.

(7) With the fan running on the high speed

setting, operate the air control lever through all ranges
and ensure that the operation is correct.

Right hand side view of the heater unit.

To Adjust Temperature Control Rod and Cable

If the temperature control rod requires adjust-

ment it will be necessary to remove the heater unit
from the vehicle. Follow the procedure described
under the heading To Remove and Install Heater Unit.

(1) Working in the passenger footwell disconnect

the temperature control cable from the clip on the side
of the heater unit.

(2) Set the heater controls to the maximum heat

position.

(3) Hold the air mix door lever clockwise while

lightly pulling on the outer control cable to remove
slack, then install the control cable into the retaining
clip.

(4) With the engine at operating temperature

check the operation of the temperature control lever.

TO ADJUST HEATER CONTROLS

To Adjust Air Control Door Rods and Cable

(1) Disconnect the air control cable from the

side link.

(2) Working on the right hand side of the heater

unit disconnect the upper and lower door lever and
demist door lever rods from the retaining clips.

(3) Hold the side link fully anti-clockwise.
(4) Hold the upper and lower door levers fully

To Adjust Air Control Cable

(1) Working in the passenger footwell, discon-

nect the intake air control cable from the clip on the
intake unit.

(2) Set the air intake lever to the recirculate

position.

(3) Hold the intake lever towards the front of the

vehicle and install the control cable into the
retaining
clip.

(4) Check the operation of the air intake control.

Cooling and Heating Systems

11. BLOWER FAN

TO REMOVE AND INSTAL

(1) Disconnect the negative battery terminal.
(2) Working below the glove 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 blower 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, condenser, 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 authorized dealer.

In the event of major repairs to the vehicle such as

engine removal, the compressor 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.