engine FIAT UNO 1983 Service Manual PDF

Fault finding - mechanical breaker ignition system
Ignition system 4•9
4
Engine fails to start
m mLoose battery connections
m mDischarged battery
m mOil in contact points
m mDisconnected ignition leads
m mFaulty condenser
Engine overheats, lacks power
m
mSeized distributor weights
m mPerforated vacuum pipe
m mIncorrect ignition timing
Engine starts and runs but misfires
m
mFaulty spark plug
m mCracked distributor cap
m mCracked rotor arm
m mWorn advance mechanism
m mIncorrect spark plug gap
m mIncorrect contact points gap
m mFaulty condenser
m mFaulty coil
m mIncorrect timing
m mPoor engine/transmission earth connections
Fault finding - Digiplex (electronic) ignition system
Engine fails to start
m
mExcessive gap on TDC sensor
m mTDC or engine speed sensor short circuited or earthed
m mDefective ignition control unit
m mControl unit multi-plug contacts corroded
m mDefective coil
Engine lacks power, high fuel consumption
m
mIncorrect ignition advance
m mTDC sensor incorrectly set
m mDistributor vacuum hose blocked

20By connecting a pressurised container to
the master cylinder fluid reservoir, bleeding is
then carried out by simply opening each bleed
screw in turn and allowing the fluid to run out,
rather like turning on a tap, until no air is
visible in the expelled fluid.
21By using this method, the large reserve of
hydraulic fluid provides a safeguard against
air being drawn into the master cylinder
during bleeding which often occurs if the fluid
level in the reservoir is not maintained.
22Pressure bleeding is particularly effective
when bleeding “difficult” systems or when
bleeding the complete system at time of
routine fluid renewal.
All methods
23When bleeding is completed, check and
top up the fluid level in the master cylinder
reservoir.
24Check the feel of the brake pedal. If it
feels at all spongy, air must still be present in
the system and further bleeding is indicated.
Failure to bleed satisfactorily after a
reasonable period of the bleeding operation,
may be due to worn master cylinder seals.
25Discard brake fluid which has been
expelled. lt is almost certain to be
contaminated with moisture, air and dirt
making it unsuitable for further use. Clean
fluid should always be stored in an airtight
container as it absorbs moisture readily
(hygroscopic) which lowers its boiling point
and could affect braking performance under
severe conditions.
13 Vacuum servo unit-
description
A vacuum servo unit is fitted into the brake
hydraulic circuit on 55 and 70 models in series
with the master cylinder, to provide assistance
to the driver when the brake pedal is
depressed. This reduces the effort required by
the driver to operate the brakes under all
braking conditions.
The unit operates by vacuum obtained from
the induction manifold and comprises basically
a booster diaphragm and non-return valve. The
servo unit and hydraulic master cylinder are
connected together so that the servo unit
piston rod acts as the master cylinder pushrod.
The driver’s braking effort is transmitted
through another pushrod to the servo unit
piston and its built-in control system. The servo
unit piston does not fit tightly into the cylinder,
but has a strong diaphragm to keep its edges
in constant contact with the cylinder wall, so
assuring an air tight seal between the two
parts. The forward chamber is held under
vacuum conditions created in the inlet manifold
of the engine and, during periods when the
brake pedal is not in use, the controls open a
passage to the rear chamber so placing it
under vacuum conditions as well. When the
brake pedal is depressed, the vacuum passageto the rear chamber is cut off and the chamber
opened to atmospheric pressure. The
consequent rush of air pushes the servo piston
forward in the vacuum chamber and operates
the main pushrod to the master cylinder.
The controls are designed so that
assistance is given under all conditions and,
when the brakes are not required, vacuum in
the rear chamber is established when the
brake pedal is released. All air from the
atmosphere entering the rear chamber is
passed through a small air filter.
Under normal operating conditions, the
vacuum servo unit is very reliable and does
not require overhaul except at very high
mileages. In this case, it is far better to obtain
a service exchange unit, rather than repair the
original unit.
It is emphasised that the servo unit assists
in reducing the braking effort required at the
foot pedal and in the event of its failure, the
hydraulic braking system is in no way affected
except that the need for higher pressures will
be noticed.
14 Vacuum servo unit-
servicing and testing
1Regularly, check that the vacuum hose
which runs between the servo unit and the
inlet manifold is in good condition and is a
tight fit at both ends.
2If broken or badly clogged, renew the air
filter which is located around the brake pedal
push rod. Access to this is obtained by
disconnecting the pushrod from the
cross-shaft or pedal arm, withdrawing the
pushrod, dust excluding boot and end cap.
3If the new filter is cut diagonally from its
centre hole, future renewal can be carried out
without the need for disconnection of the
pushrod.
4If the efficiency of the servo unit is suspect,
it can be checked out in the following way.
5Run the engine, then switch off the ignition.
Depress the footbrake pedal; the distinctive
in-rush of air into the servo should be clearly
heard. It should be possible to repeat this
operation several times before the vacuum in
the system is exhausted.
6Start the engine and have an assistant
apply the footbrake pedal and hold it down.
Disconnect the vacuuum hose from the servo.
There should not be any in-rush of air into the
servo through the connecting stub. lf there is,
the servo diaphragm is probably faulty. During
this test, expect the engine to idle roughly,
unless the open end of the hose to the inlet
manifold is plugged. Reconnect the hose.
7With the engine off, depress the brake
pedal fully. Start the engine with the brake
pedal still depressed; the pedal should be felt
to go down fractionally.
8If the results of these tests are not
satisfactory, remove the unit and fit a new one
as described in the next Section.
15 Vacuum servo unit-
removal and refitting
3
1Syphon as much fluid as possible out of the
master cylinder reservolr.
2Disconnect electrical leads from the
terminals in the reservoir cap then uncouple
the rigid pipelines from the master cylinder
body. Be prepared to catch leaking fluid and
plug the open ends of the pipelines.
3The master cylinder can be unbolted now
from the servo unit, or detached later when
the complete assembly is withdrawn.
4Working inside the car, disconnect the
servo pushrod from the pedal then remove the
servo mounting nuts.
5Withdraw the servo assembly into the
engine compartment, then remove it to the
bench. lf the master cylinder is still attached,
cover the wings with protective sheeting, in
case brake fluid is spilled during removal.
6Refitting is a reversal of the removal
process, but adjust the pushrod clearance as
described in Section 9. On completion of
refitting, bleed the complete hydraulic system
as described in Section 12. Note: Where the
help of an assistant is available, the servo
pushrod need not be disconnected from the
pedal. The rod is a sliding fit in the servo and
the servo can be simply pulled off the rod.
Refitting without having disconnected the rod
from the pedal can be difficult unless the help
of an assistant is available.
16 Handbrake- adjustment
1
Adjustment is normally automatic, by the
movement of the rear brake shoes on their
automatic adjusters.
However, owing to cable stretch,
supplementary adjustment is occasionally
required at the control lever adjuster nut. The
need for this adjustment is usually indicated
by excessive movement of the control lever
when fully applied.
1The rear brakes should be fully applied
when the handbrake control lever has been
pulled over four or five notches.
2If adjustment is required, release the
8•8 Braking system
16.2 Handbrake adjuster nuts

1 General description
The electrical system is of 12 volt negative
earth type and employs a belt-driven
alternator and a pre-engaged type starter
motor.
The models in the range are all adequately
equipped with electrical accessories, while SX
versions also have power windows and
centralised door locking plus a check control
system (Section 34).
2 Battery- inspection, charging,
removal and refitting
2
1The battery is of maintenance-free type and
under normal circumstances, no topping up
will be required, but regularly check that the
electrolyte level is between the minimum and
maximum lines on the translucent battery
casing.
2If the electrolyte level does drop below theminimum line, suspect a leak in the battery
casing or that the alternator is overcharging. If
the latter is the case, rectify the alternator fault
and then prise out the two rectangular plugs
from the top of the battery and top up with
distilled or purified water.
3Always keep the battery terminals clean
and smear them with petroleum jelly to
prevent corrosion.
4The battery will normally be kept fully
charged by the alternator, but it is possible for
the battery to become discharged if the daily
mileage is very low with much use being
made of the starter and electrical accessories.
5When the battery begins to deteriorate with
age it may also require a boost from a mains
charger.
6Disconnect both battery leads before
connecting the mains charger. 7To remove the battery from the car, first
disconnect the leads from the battery
terminals (earth first) and then unscrew the
securing clamp from the casing projection at
the base of the casing (photo).
8Lift the battery from its mounting platform.
Refitting is a reversal of removal. Reconnect
the earth cable last.
Fuses
Circuit protected Fuse rating (A)
1 Stop lamps, direction indicator lamps, instrument panel warning
lamps, tachometer economy gauge, check control system . . . . . . 10
2 Windscreen wiper and washer, rear screen wiper/washer, check
system panel illumination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
3 Left front parking, right rear tail lamp, cigar lighter illumination,
heater control and clock, digital clock illumination . . . . . . . . . . . . . 7.5
4 Right front parking lamp and left rear tail lamp, instrument panel
illumination and rear number plate lamp . . . . . . . . . . . . . . . . . . . . . 7.5
5 Left-hand dipped headlamp, rear foglamps . . . . . . . . . . . . . . . . . . 10
6 Right-hand dipped headlamp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
7 Left-hand headlamp (main beam) . . . . . . . . . . . . . . . . . . . . . . . . . . 10
8 Right-hand headlamp (main beam) . . . . . . . . . . . . . . . . . . . . . . . . . 10
9 Engine cooling fan and horn (Comfort) . . . . . . . . . . . . . . . . . . . . . . 25
10 Heater booster fan, digital clock map reading lamp . . . . . . . . . . . . 20
11 Heated tailgate glass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
12 Courtesy lamps, cigar lighter, radio power feed, disc pad
sensors, economy gauge (ES models) . . . . . . . . . . . . . . . . . . . . . . 10
13 Hazard warning lamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
14 Spare (Comfort), Horn (Super) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
BulbsWattage
Headlamp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40/45 or Halogen H4 60/55
Front parking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Side repeater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Tail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Stop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Reversing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Rear foglamp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Direction indicator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Rear number plate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Courtesy lamp (roof) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Courtesy lamp (pillar) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Warning and indicator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Wedge base
Torque wrench settingsNm lbf ft
Alternator mounting and adjustment nuts . . . . . . . . . . . . . . . . . . . . . . . 50 87
Starter motor bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 35
9•2 Electrical system
2.7 Battery clamp
If battery terminal corrosion
has occurred, it may be
neutralised by applying
sodium bicarbonate or
household ammonia.

3 Alternator-
maintenance and precautions
1
To avoid damage to the alternator, the
following precautions should be observed.
1Disconnect the leads from the battery
before connecting a mains charger to the
battery terminals.
2Never stop the engine by pulling off one of
the battery leads.
3Disconnect the battery if electric welding is
to be carried out on the vehicle.
4If using booster cables from another battery
to start the car, make sure that they are
connected positive to positive and negative to
negative.
5Maintenance consists of keeping the
outside of the alternator clean, the electrical
connections secure and the drivebelt correctly
tensioned, see Chapter 2, Section 8.
4 Alternator-
removal and refitting
1
Note: Depending on the model, access to the
alternator from above may be poor in which
case it will be necessary to work from the
underside of the vehicle, through the
right-hand wheel arch (after removing the
roadwheel and the lower undershield). Refer
to Chapter 13 for details.
1Disconnect the leads from the rear of the
alternator.2Release the mounting and adjuster link nuts
and push the alternator as far as it will go in
towards the engine (photos).
3Slip the drivebelt from the pulley.
4Remove the mounting and adjuster bolts
and lift the alternator from the brackets on the
engine. Remove downwards on 1116 cc and
1301 cc models.
5Refitting is a reversal of removal, tension
the drivebelt as described in Chapter 2,
Section 8.
5 Alternator- overhaul
3
1Overhaul of the alternator should be limited
to renewal of the brushes. If the unit has
covered a high mileage, it will be found moreeconomical to exchange it for a new or
factory-reconditioned one, rather than renew
worn components on the original unit.
Brush renewal
(Marelli alternator)
2Unscrew the nuts and take off the rear cover.
3Unscrew the two small bolts and withdraw
the brush holder (photos).
4Fit the new brush holder which is supplied
complete with brushes, by reversing the
removal operations.
Brush renewal
(Bosch alternator)
5Where applicable, remove the radio
suppression condenser (capacitor) from the
rear end frame (one screw and washer, and a
plug-in connection).
6Undo the two screws which retain the brush
holder to the rear frame of the alternator, then
Electrical system 9•3
5.3A Alternator brush holder bolt4.2B Alternator adjuster bolt4.2A Alternator mounting
Fig. 9.1 Exploded view of typical alternator (Sec 5)
1 Pulley
2 Fan
3 Bolts
4 Washers
5 Drive-end bracket
6 Stator windings
7 Plate screw
8 Diode plate
(rectifier pack)9 Body
10 Brush
11 Spring
12 Brush holder
13 Condenser
14 Screws and
washers
15 Screws and
washers16 Screws and
washers
17 Plug socket
18 Suppressor
19 Shaft nut
20 Spring washer
21 Thrust ring
22 Bearing
23 Retainer plate24 Thrust ring
25 Spring washer
26 Screw and washer
27 Key
28 Rotor
29 Bearing
30 Backing washer
31 Shield (where
applicable)
5.3B Removing alternator brush holder
9

ease the holder out of the alternator. Inspect
the brushes and if worn below the specified
minimum length, they must be renewed.
7Disconnect the brush leads by unsoldering
or carefully cutting them.
8When soldering the new brush leads, do
not allow solder to run down them or their
flexibility will be ruined.
9When inspecting or renewing brushes,
check the surface of the slip rings. Clean them
with solvent or if they are very discoloured,
use very fine glasspaper.
6 Voltage regulator
1This is of integral type and is part of the
brushholder assembly.
2No provision is made for adjustment or
overhaul.
7 Starter motor-
description and testing
2
1The starter motor may be one of two
different makes. Both are of pre-engaged
type.
2This type of starter motor incorporates a
solenoid mounted on top of the starter motor
body. When the ignition switch is operated,
the solenoid moves the starter drive pinion,
through the medium of the shift lever, into
engagement with the flywheel starter ring
gear. As the solenoid reaches the end of its
stroke, and with the pinion by now partially
engaged with the flywheel ring gear, the main
fixed and moving contacts close and engage
the starter motor to rotate the engine.
3This pre-engagement of the starter drive
does much to reduce the wear on the flywheel
ring gear associated with inertia type starter
motors.
4If the starter fails, some fault-finding can be
done with it still on the car. Check the ignition
warning light comes on, and does not go out
when the starter is switched on. If it goes out,
the fault is probably in the battery. If it stays
bright, get an assistant to work the switch,whilst listening to the starter. Listen to find out
if the solenoid clicks into position. If it does
not, pull off the solenoid wire, and check it
with a test bulb. If the wire is live when the key
is turned, but the solenoid does not move,
take off the starter and remove it to the bench
for overhaul.
8 Starter motor-
removal and refitting
1
1Disconnect the battery negative lead.
2Disconnect the lead from the starter motor
(photo).
3Unscrew the fixing bolts and withdraw the
starter motor, downwards on 1116 cc and
1301 cc models (photo).
4Refitting is a reversal of the removal
procedure.
9 Starter motor- overhaul
3
1As with the alternator, the operations
should normally be limited to renewal of the
brushes. If the unit has covered a high
mileage it will usually be more economical to
purchase a new or factory-reconditioned one
rather than renew several components of the
original unit.
2Owing to the possibility that a fault can
develop in the starter motor solenoid or drive
assembly, full dismantling procedures are
given later in this Section.
Brush - renewal
3Slide off the cover band.
4Using a hooked piece of wire, pull up the
springs so that the brushes can be withdrawn
and their lengths checked for wear. If they
have worn below the specified minimum
length, renew them by extracting the brush
lead connecting screws (photo).
Solenoid
5Disconnect the field connecting wire from
the solenoid.
6Unscrew the bolts which hold the solenoid
to the end-frame.
7Unscrew the yoke tie-rod nuts.
9•4 Electrical system
9.4 Starter motor brush partly withdrawn
8.2 Starter motor connections8.3 Removing starter motor
Fig. 9.2 Exploded view of typical starter motor (Sec 9)
1 Armature
2 Drive pinion/clutch3 Drive end bracket
4 Shift lever5 Solenoid
6 Brush endplate7 Brush
8 Field windings
Gripping the brush leads with
a pair of pliers to act as a
heat sink will prevent heat
transfer to the internal
components of the alternator.

them. Carefully release the fibre optic
filaments (photos).
6A push-button switch can be removed by
compressing its retaining tabs and pushing it
from the panel.
7A rocker switch can be removed if its knob
is pulled off and the switch sections
withdrawn from the panel.
8Reassembly and refitting of both types of
switches are reversals of removal and
dismantling.
14 Tailgate contacts
1
1Contact blocks are used to transmit power
to the heated tailgate window and to the wiper
motor.
2The block on the tailgate or the body may
be released by prising their ends with a
screwdriver (photos).
15 Horns
1
1These are mounted close to the
engine/transmission left-hand mounting
below the radiator.
2Apart from keeping the connecting leads
secure, no maintenance or adjustment is
required.
16 Headlamp bulb- renewal
1
1Open the bonnet and pull off the plug and
the rubber cover from the rear of the
headlamp (photo).
2Prise back the spring bulbholder clips and
withdraw the combined bulb and holder
(photos).
3Refit the new bulb. Avoid fingering it if it is
of halogen type. Should the fingers touch the
bulb, wipe it with a rag soaked in methylated
spirit to remove any residual grease.
4Turn the bulbholder until the pip on its
flange engages in the cut-out in the rim of the
reflector.
5Snap back the spring retaining clips, refit
the rubber cover and reconnect the plug.
17 Headlamp beam- alignment
2
1It is recommended that the headlamp
beams are aligned by your dealer or a service
station having optical setting equipment.
2Where an owner wishes to do the job
himself, proceed in the following way.
3Have the car standing on a level floor with
9•6 Electrical system
Fig. 9.3 Headlamp beam adjustment
screws (Sec 17)
A Vertical B Horizontal
16.2B Headlamp halogen type bulb16.2A Headlamp bulbholder spring
clips
14.2B Body contact block
16.1 Headlamp plug and rubber
cover
14.2A Tailgate contact block13.5B Switch panel fibre optic13.5A Withdrawing switch panel

27 Tailgate wiper motor-
removal and refitting
1
1Remove the blade and arm as previously
described. Unscrew the drive spindle bezel
nut.
2Open the tailgate fully.
3Unclip and remove the wiper motor cover.
4Unscrew the mounting screws, withdraw
the motor and disconnect the wiring plug
(photo).
5Refitting is a reversal of removal.
28 Washer system
1
1The washer system for the windscreen and
the tailgate operates from a bag type fluid
reservoir within the engine compartment
(photo).
2The reservoir bag is fitted with two pumps,
one for each system (photo).
3Use screen cleaning fluid mixed in the
recommended proportion in the washer fluid
reservoir and in very cold weather add a small
quantity of methylated spirit.
4To clear a blocked washer jet nozzle or to
adjust the wash jet glass-striking pattern,
insert a pin part way into the jet nozzle.
29 Heated tailgate window-
precautions and repair
2
1The heater element inside the tailgate glass
should be treated with care.
2Clean only with a damp cloth and wipe in
the direction in which the filaments run. Avoid
scratching with rings on the fingers, or by
allowing luggage to rub on the glass. Never
stick adhesive labels over the heater element.
3Should one of the heater filaments be
broken it can be repaired using one of the
special silver paints available, but follow the
manufacturer’s instructions carefully.
30 Radio/cassette- fitting
2
1In-car entertainment equipment is not
provided as standard on the models covered
by this Manual.
2However, the centre console is designed to
receive a radio set after removing the blanking
plate behind which a power lead is already
provided.
3The ignition system and other electrical
components are suppressed during
production of the car and further suppression
should not be required other than earthing the
wiper motor.
Receiver
4Fit the radio/cassette using the installation
kit supplied with the equipment.
5On Comfort models, fit an in-line fuse in the
power feed. On Super models the radio
supply is protected by fuse number 12.
6Make sure that the radio is well earthed to a
metal body component.
Aerial
7The recommended locations for the aerial
are towards the rear of the right-hand front
wing or on the windscreen pillar.
8Fitting instructions for Fiat aerials are
supplied with them, but the following general
advice will help if using non-Fiat equipment.9Motorised automatic aerials rise when the
equipment is switched on and retract at
switch-off. They require more fitting space
and supply leads, and can be a source of
trouble.
10There is no merit in choosing a very long
aerial as, for example, the type about three
metres in length which hooks or clips on to
the rear of the car, since part of this aerial will
inevitably be located in an interference field.
For VHF/FM radios the best length of aerial is
about one metre. Active aerials have a
transistor amplifier mounted at the base and
this serves to boost the received signal. The
aerial rod is sometimes rather shorter than
normal passive types.
11A large loss of signal can occur in the
aerial feeder cable, especially over the Very
High Frequency (VHF) bands. The design of
feeder cable is invariably in the co-axial form,
ie a centre conductor surrounded by a flexible
copper braid forming the outer (earth)
conductor. Between the inner and outer
conductors is an insulator material which can
be in solid or stranded form. Apart from
insulation, its purpose is to maintain the
correct spacing and concentricity. Loss of
signal occurs in this insulator, the loss usually
being greater in a poor quality cable. The
quality of cable used is reflected in the price
of the aerial with the attached feeder cable.
12The capacitance of the feeder should be
within the range 65 to 75 picofarads (pF)
approximately (95 to 100 pF for Japanese and
American equipment), otherwise the
adjustment of the car radio aerial trimmer may
not be possible. An extension cable is
necessary for a long run between aerial and
receiver. If this adds capacitance in excess of
the above limits, a connector containing a
series capacitor will be required, or an
extension which is labelled as
“capacity-compensated”.
13Fitting the aerial will normally involve
making a 7/8 in (22 mm) diameter hole in the
bodywork, but read the instructions that come
with the aerial kit. Once the hole position has
been selected, use a centre punch to guide
the drill. Use sticky masking tape around the
area for this helps with marking out and drill
location, and gives protection to the
9•10 Electrical system
Fig. 9.8 Radio housing and power lead (A)
(Sec 30)
28.2 Washer pumps28.1 Washer fluid reservoir27.4 Tailgate wiper motor

paintwork should the drill slip. Three methods
of making the hole are in use:
a) Use a hole saw in the electric drill. This is,
in effect, a circular hacksaw blade
wrapped round a former with a centre
pilot drill.
b) Use a tank cutter which also has cutting
teeth, but is made to shear the metal by
tightening with an Allen key.
c) The hard way of drilling out the circle is
using a small drill, say 1/8 in (3 mm), so
that the holes overlap. The centre metal
drops out and the hole is finished with
round and half-round files.
14Whichever method is used, the burr is
removed from the body metal and paint
removed from the underside. The aerial is fitted
tightly ensuring that the earth fixing, usually a
serrated washer, ring or clamp, is making a
solid connection. This earth connection is
important in reducing interference. Cover any
bare metal with primer paint and topcoat, and
follow by underseal if desired.
15Aerial feeder cable routing should avoid
the engine compartment and areas where
stress might occur, eg under the carpet where
feet will be located.Loudspeakers
16A mono speaker may be located under
the facia panel beneath the glovebox.
17Provision is made for twin speakers within
the door tidy bins or under the rear shelf
mountings.
18Speakers should be matched to the
output stage of the equipment, particularly as
regards the recommended impedance. Power
transistors used for driving speakers are
sensitive to the loading placed on them.
31 Electrically-operated front
door windows
3
1The electrically-operated front door
windows are controlled by switches on the
centre console or in the door armrest
(depending on model). The regulator motor
and cable are located within the door cavity.
2To gain access to the assembly, remove
the door trim panel as described in Chap-
ter 12.
3Disconnect the wiring plug (1) (Fig. 9.11).4Release the bolts which connect the power
lift to the glass mounting.
5Remove the bolts which hold the lift
assembly to the door.
6The motor and glass mounting may be
disconnected from the cable guide and sleeve
and any faulty components renewed.
7When refitting the assembly to the door,
make sure that the window glass slides
smoothly before fully tightening the cable
guide bolts. Refer to Section 10 for details of
system fuses and relays.
32 Central door locking system
1
1The doors are locked simultaneously from
the outside by turning the key in either
direction.
2The doors can be locked from inside the car
in the following ways:
All doors locked or unlocked - depress or lift
a front door lock plunger knob.
One rear door locked or unlocked - depress
or lift a rear door lock plunger knob.
Electrical system 9•11
Fig. 9.9 Door speaker mounting (Sec 30)Fig. 9.10 Rear speaker mounting (Sec 30)
Fig. 9.13 Central door locking system
components (Sec 32)Fig. 9.12 Power operated window
components (Sec 31)Fig. 9.11 Power-operated window motor
(Sec 31)
1 Connector plug
1 Electric motor
2 Glass mounting
3 Cable guide4 Cable
5 Cable sleeve1 Solenoid
2 Lock relay lever
3 Link rod4 Exterior handle
lever
9

3The centralised door locking system can
operate independently of the key.
4To gain access to the lock solenoid and
linkage, remove the front door trim panel as
described in Chapter 12.
5Disconnect the battery negative lead.
6Disconnect the electrical wiring plugs from
the solenoid within the door cavity.
7Disconnect the solenoid from the lock lever
by removing the clip.
8Unscrew the two bolts which secure the
solenoid to the door and remove it.
9Renew the solenoid or switch as necessary.
10Refitting is a reversal of removal.
11Refer to Section 10 for details of system
fuses and relays.
33 Economy gauge
(Econometer)
2
1This device is fitted to ES (energy saving)
models and indicates to the driver the fuel
consumption (in litres per 100 km) coupled
with a needle which moves over coloured
sections of a dial to make the driver aware
that his method of driving is either conducive
to high or low fuel consumption. Refer to
Chapter 3, Section 16.
2The device is essentially a vacuum gauge
which also incorporates a warning lamp to
indicate to the driver when a change of gear is
required.
3A fuel cut-out valve (see Chapter 3, Sec-
tion 11) is used in conjunction with the
economy gauge so that when the accelerator
pedal is released during a pre-determined
engine speed range, fuel supply to the engine
is stopped, but resumes when the engine
speed falls below the specified range.
LED (light emitter diode)
4The gearchange indicator will only light up
at engine speeds in excess of 2000 rev/min
for vacuum pressures up to 600 mm Hg in 1st,
2nd and 3rd speed gears and for vacuum
pressures up to 676 mm Hg in 4th speedgear. The light will not come on if 5th speed
gear is engaged or if the coolant temperature
is below 55ºC.
5There is a two second delay in the light
coming on to prevent it operating during rapid
acceleration in a low gear.
6If the LED light comes on during
deceleration it should be ignored.
Fault finding
7A faulty economy gauge should be checked
in the following way.
8Refer to Section 21 and remove the
instrument panel.
9Disconnect the economy gauge L
connector and then connect a test lamp
between the BN cable contact and earth. If
the lamp comes on then the gauge supply
circuit is not open. If the lamp does not come
on, check all connections in the supply cable
which comes from the interconnecting unit of
the electrical system, also Fuse No 12.
10Now connect a voltmeter between the
white cable and earth. Check the voltage with
the engine not running, but the ignition
switched on. It should be between 0.7 and
0.9 volt. If the reading varies considerably
from that specified, check the connections
between the economy gauge and the fuel
cut-out device control unit. If the fault cannot
be rectified, renew the ignition control unit
(Digiplex system, see Chapter 4).
11Now check the closed throttle valve plate
switch by connecting a voltmeter between the
brown and BN cables of the L connector. With
the valve plate open, there should be no
reading, but with it open, voltage should be
indicated.
12Failure to conform as described will be
due to a faulty earth in the switch or a faulty
fuel cut-out device control unit.
13A further test of the throttle valve plate
switch may be carried out by disconnecting
the multi-plug from the fuel cut-out device
control unit.
14Connect a test lamp to contact 4 (positive
battery terminal). The lamp should come on,
when the engine is idling or the accelerator
released. If it does not, renew the throttle
valve plate switch.15Connect a tachometer to the brown/white
cable contact in the L connector and record
the engine speed with the engine running. If
no reading is obtained, renew the Digiplex
ignition control unit which must be faulty.
34 Check control (warning
module) system
2
1This is fitted into the instrument panel of
certain models to provide a means of
checking the operation of many electrical
circuits and other systems in the interest of
safety. Sensors are used where appropriate.
2The following components are not
monitored by the system, but have separate
warning lamps:
Handbrake “on”
Choke in use
Low engine oil pressure
Battery charge indicator
3The multi-functional electronic device
automatically checks the following functions
whether the engine is running or not:
Coolant level
Disc pad wear
Door closure
Engine oil level
Front parking lamps
Rear foglamps
Stop lamps
4The check information is stored by the
system monitor until the engine is started
when the display panel then indicates the
situation by means of the LEDs (light emitter
diodes) and the general lamp.
5If all functions are in order, the green panel
lamp will come on when the ignition key is
turned and will go out after two to three
seconds.
6If some functions are not in order, then the
red panel lamp will come on also the
appropriate LED.
Sensors - checking
7If a fault signal occurs which is
subsequently found to be incorrect, first
check the wiring connections between the
9•12 Electrical system
Fig. 9.15 Check system control panel (Sec 34)
A Parking lamps
B Coolant levelC Engine oil level
D Door closureE Brake fluid level
F Disc pad wearFig. 9.14 Location of control units (Sec 33)
A Digiplex ignition system control unit
B Fuel cut-out valve control unit

9•14 Electrical system
Fault finding - electrical system
No voltage at starter motor
m mBattery discharged
m mBattery defective internally
m mBattery terminals loose or earth lead not securely attached to body
m mLoose or broken connections in starter motor circuit
m mStarter motor switch or solenoid faulty
Voltage at starter motor - faulty motor
m
mStarter brushes badly worn, sticking, or brush wires loose
m mCommutator dirty, worn or burnt
m mStarter motor armature faulty
m mField coils earthed
Starter motor noisy or rough in engagement
m
mPinion or flywheel gear teeth broken or worn
m mStarter drive main spring broken
m mStarter motor retaining bolts loose
Alternator not charging*
m
mDrivebelt loose and slipping, or broken
m mBrushes worn, sticking, broken or dirty
m mBrush springs weak or broken
* If all appears to be well but the alternator is still not charging, take the
car to an automobile electrician for checking of the alternator
Ignition light fails to go out, battery runs flat in a
few days
m mDrivebelt loose and slipping, or broken
m mAlternator faulty
Battery will not hold charge for more than a few
days
m mBattery defective internally
m mElectrolyte level too low or electrolyte too weak due to leakage
m mPlate separators no longer fully effective
m mBattery plates severely sulphated
m mDrivebelt slipping
m mBattery terminal connections loose or corroded
m mAlternator not charging properly
m mShort in lighting circuit causing continual battery drain
Fuel gauge gives no reading
m
mFuel tank empty!
m mElectric cable between tank sender unit and gauge earthed or loose
m mFuel gauge case not earthed
m mFuel gauge supply cable interrupted
m mFuel gauge unit broken
Fuel gauge registers full all the time
m
mElectric cable between tank unit and gauge broken or disconnected
Horn operates all the time
m
mHorn push either earthed or stuck down
m mHorn cable to horn push earthed
Horn fails to operate
m
mBlown fuse
m mCable or cable connection loose, broken or disconnected
m mHorn has an internal fault
Horn emits intermittent or unsatisfactory noise
m
mCable connections loose
m mHorn incorrectly adjusted
Lights do not come on
m
mIf engine not running, battery discharged
m mLight bulb filament burnt out or bulbs broken
m mWire connections loose, disconnected or broken
m mLight switch shorting or otherwise faulty
Lights come on but fade out
m
mIf engine not running, battery discharged
Lights give very poor illumination
m
mLamp glasses dirty
m mReflector tarnished or dirty
m mLamps badly out of adjustment
m mIncorrect bulb with too low wattage fitted
m mExisting bulbs old and badly discoloured
m mElectrical wiring too thin not allowing full current to pass
Lights work erratically, flashing on and off,
especially over bumps
m mBattery terminals or earth connections loose
m mLights not earthing properly
m mContacts in light switch faulty
Wiper motor fails to work
m
mBlown fuse
m mWire connections loose, disconnected or broken
m mBrushes badly worn
m mArmature worn or faulty
m mField coils faulty
Wiper motor works very slowly and takes
excessive current
m mCommutator dirty, greasy or burnt
m mDrive spindle binding or damaged
m mArmature bearings dry or unaligned
m mArmature badly worn or faulty
Wiper motor works slowly and takes little current
m
mBrushes badly worn
m mCommutator dirty, greasy or burnt
m mArmature badly worn or faulty
Wiper motor works but wiper blade remains static
m
mDrive spindle damaged or worn
m mWiper motor gearbox parts badly worn