engine coolant temperature sensor. The
crankshaft speed/position sensor is activated
by a toothed disc on the rear of the crankshaft,
inside the cylinder block. The disc has 35
equally spaced teeth (one every 10°), with a
gap in the 36th position. The gap is used by
the sensor to determine the crankshaft
position relative to Top Dead Centre (TDC) of
No 1 piston.
The ignition advance is a function of the
ESC II module, and is controlled by vacuum.
The module is connected to the carburettor by
a vacuum pipe, and a transducer in the
module translates the vacuum signal into an
electrical voltage. From the vacuum signal, the
module determines engine load; engine speed
and temperature are determined from the
crankshaft speed/position sensor and the
engine coolant temperature sensor. The
module has a range of spark advance settings
stored in the memory, and a suitable setting is
selected for the relevant engine speed, load
and temperature. The degree of advance can
thus be constantly varied to suit the prevailing
engine speed and load conditions.
On DOHC fuel-injected engines, a
development of the EEC IV (Electronic Engine
Control IV) engine management system is
used to control both the ignition and fuel-
injection systems. The EEC IV module receives
information from a crankshaft speed/position
sensor (the same as that fitted to the
carburettor models), a throttle position sensor,
an engine coolant temperature sensor, a fuel
temperature sensor, an air charge temperature
sensor, a Manifold Absolute Pressure (MAP)
sensor, and a vehicle speed sensor (mounted
on the gearbox). Additionally, on models with
a catalytic converter, an additional input is
supplied to the EEC IV module from an
exhaust gas oxygen (HEGO) sensor. On
models with automatic transmission,
additional sensors are fitted to the
transmission to inform the EEC IV module
when the transmission is in neutral, and when
the downshift is being operated.
The module provides outputs to control the
fuel pump, fuel-injectors, idle speed, ignition
system and automatic transmission .
Additionally, on models with air conditioning,
the EEC IV module disengages the air
conditioning compressor clutch when starting
the engine or when the engine is suddenly
accelerated. On models fitted with a catalytic
converter, the EEC IV module also controls the
carbon canister purge solenoid valve.
Using the inputs from the various sensors,
the EEC IV module computes the optimum
ignition advance, and fuel-injector pulse
duration to suit the prevailing engine
conditions.
On 2.4 & 2.9 litre V6 engines, the system
operates in much the same way as that fitted
to the DOHC fuel-injected engine, noting the
following points.
a)There is no crankshaft speed/position
sensor.
b)The vehicle speed sensor is only fitted to
models equipped with a catalytic
converter.Precautions
ESC II module
Although it will tolerate all normal under-
bonnet conditions, the ESC II module may be
adversely affected by water entry during
steam cleaning or pressure washing of the
engine bay.
If cleaning the engine bay, therefore, take
care not to direct jets of water or steam at the
ESC II module. If this cannot be avoided,
remove the module completely, and protect its
multi-plug with a plastic bag.
Ignition system HT voltage
Take care to avoid receiving electric shocks
from the HT side of the ignition system. Do not
handle HT leads, or touch the distributor or
coil, when the engine is running. When tracing
faults in the HT system, use well insulated
tools to manipulate live leads. Electronic
ignition HT voltage could prove fatal.
Electronic ignition systems
General
Further details of the various systems are
given in the relevant Sections of this Chapter.
While some repair procedures are given, the
usual course of action is to renew the
component concerned. The owner whose
interest extends beyond mere component
renewal should obtain a copy of the
Automobile Electrical & Electronic Systems
Manual, available from the publishers of this
manual.
It is necessary to take extra care when
working on the electrical system, to avoid
damage to semi-conductor devices (diodes
and transistors), and to avoid the risk of
personal injury. In addition to the precautions
given in Safety first!at the beginning of this
manual, observe the following when working
on the system:
Always remove rings, watches, etc before
working on the electrical system.Even with the
battery disconnected, capacitive discharge
could occur if a component’s live terminal is
earthed through a metal object. This could
cause a shock or nasty burn.
Do not reverse the battery connections.
Components such as the alternator, electronic
control units, or any other components having
semi-conductor circuitry, could be irreparably
damaged.
If the engine is being started using jump
leads and a slave battery, connect thebatteries positive-to-positiveand negative-to-
negative(see “Jump starting”). This also
applies when connecting a battery charger.
Never disconnect the battery terminals, the
alternator, any electrical wiring, or any test
instruments, when the engine is running.
Do not allow the engine to turn the alternator
when the alternator is not connected.
Never test for alternator output by “flashing”
the output lead to earth.
Never use an ohmmeter of the type
incorporating a hand-cranked generator for
circuit or continuity testing.
Always ensure that the battery negative lead
is disconnected when working on the
electrical system.
Before using electric-arc welding equipment
on the car, disconnect the battery, alternator,
and components such as the fuel-
injection/ignition electronic control unit, to
protect them from the risk of damage.
Refer to Chapter 13
1In normal use the battery should not require
charging from an external source, unless the
vehicle is laid up for long periods, when it
should be recharged every six weeks or so. If
vehicle use consists entirely of short runs in
darkness it is also possible for the battery to
become discharged. Otherwise, a regular
need for recharging points to a fault in the
battery or elsewhere in the charging system.
2There is no need to disconnect the battery
from the vehicle wiring when using a battery
charger, but switch off the ignition and leave
the bonnet open.
3Domestic battery chargers (up to about 6
amps output) may safely be used overnight
without special precautions. Make sure that
the charger is set to deliver 12 volts before
connecting it. Connect the leads (red or
positive to the positive terminal, black or
negative to the negative terminal) before
switching the charger on at the mains.
4When charging is complete, switch off at
the mains beforedisconnecting the charger
from the battery. Remember that the battery
will be giving off hydrogen gas, which is
potentially explosive.
5Charging at a higher rate should only be
carried out under carefully controlled
conditions. Very rapid or “boost” charging
should be avoided if possible, as it is liable to
cause permanent damage to the battery
through overheating.
6During any sort of charging, battery
electrolyte temperature should never exceed
38°C (100°F). If the battery becomes hot, or
the electrolyte is effervescing vigorously,
charging should be stopped.
3Battery - charging
2Electrical fault-finding - general
information
Engine electrical systems 5•3
5
Warning. The voltages produced
by the electronic ignition system
are considerably higher than those
produced by conventional
systems. Extreme care must be taken when
working on the system with the ignition
switched on. Persons with surgically-
implanted cardiac pacemaker devices
should keep well clear of the ignition
circuits, components and test equipment.
procarmanuals.com
multi-plug. Disconnect the plug, pulling on the
plug itself, not the wires (see illustration).
6Make alignment marks between the
distributor body and the engine, then remove
the distributor clamp bolt and clamp plate
(see illustration). On V6 models access is
poor, and a crow’s-foot spanner will be
needed. The clamp bolt may be covered insealant to discourage tampering - if so, scrape
it off. Unbolt the support bracket, when fitted.
7Lift out the distributor (see illustration).
Mark the position taken up by the rotor arm
after removal.
8If the distributor is mechanically or
electrically defective, it must be renewed. The
only spares available are the cap, rotor arm,
module (when applicable) and the shaft O-ring
(see illustration).
9Commence refitting by positioning the rotor
arm to the point noted in paragraph 7. This will
be approximately 20°clockwise from the No 1
firing point (paragraph 4)(see illustration).
10Make sure that the engine is stillpositioned at the firing point for No1 cylinder.
11Offer the distributor to the engine,
observing the distributor body-to-engine
alignment marks. As the drivegear meshes,
the distributor shaft will turn anti-clockwise.
The rotor arm should end up in the correct
position for No1 firing - if not, withdraw the
distributor, re-position the shaft and try again.
5•6Engine electrical systems
13.6 Distributor clamp bolt (arrowed)
13.8 Distributor shaft O-ring
13.7 Removing the distributor
13.5 Disconnecting a distributor multi-plug
13.3 Distributor rotor arm positions before removal - No 1 firing point
A Carburettor modelsB OHC fuel-injection modelsC V6 models
13.9 Distributor rotor arm positions ready for refitting
A Carburettor modelsB OHC fuel-injection modelsC V6 models
procarmanuals.com
6Disconnect the glovebox arms and hinges.
Withdraw the hinge pins and remove the lid.
7Slide the auxiliary fuse panel off its
mounting and remove the glovebox light
(when fitted).
8Remove the ABS and ESC/EEC modules
(Chapter 13). Remove the two nuts and
washers from inside the glovebox.
9Remove the radio, stowage box or graphic
equaliser, ashtray, cigarette lighter panel and
(when applicable) the gear lever gaiter.
10Remove the centre console, disconnecting
switches, rear heater controls etc as
necessary.
11Remove the six screws which secure the
passenger’s side lower panel. Remove the
panel. 12Refit by reversing the removal operations,
transferring the brackets, captive nuts or other
fittings to any new panels being fitted.
Models from April 1992
13Disconnect the battery negative terminal.
14Remove the centre console.
15Remove the radio, amplifier unit and
(where necessary) the CD player.
16Remove the instrument cluster.
17Remove the steering wheel and then the
steering column direction indicator/headlight
flasher switch and windscreen wipe/wash
switch.
18Pull off the three knobs from the heater
and ventilation controls to gain access to the
two hidden central vent panel retainingscrews. Slacken and remove the four panel
retaining screws and partially withdraw the
panel. Disconnect the wiring connectors from
the heated window switches and fuel
computer (where fitted) and remove the panel
from the car (see illustrations).
19Undo the two retaining screws and free
the heater and ventilation control panel from
the facia panel (see illustration).
20Depress the retaining tang, situated at the
bottom of the control knob, and remove the
light switch knob from the switch (see
illustration).
21Withdraw the light switch from right-hand
vent panel and disconnect the wiring plug (see
illustration).
22Remove the light switch surround from the
vent panel and disconnect the wiring
connector (see illustration).
23Undo the three retaining screws and
remove the right-hand vent panel from the
facia (see illustration).
24Remove the ashtray insert, then slacken
and remove the three ashtray retaining
screws. Remove the ashtray assembly,
detaching the illumination lamp as it is
removed (see illustration).
25Undo the retaining screw then disconnect
the wiring plugs and remove the cigarette
lighter from the facia panel (see illustration).
26Unclip and remove both the left- and right-
hand facia undercover panels.
27Carefully prise out the bonnet release lever
surround to gain access to the lever retaining
Bodywork and fittings 12•13
12
41.18a Remove the control knobs to gain
access to the two hidden central vent
panel retaining screws (arrowed)41.18b Withdraw the central vent panel and
disconnect the heated window and fuel
computer wiring connectors41.19 Undo the heater control panel
retaining screws and free the panel from
the facia
41.22 Withdraw the light switch surround
and disconnect the wiring connector
41.20 Depress the tang (arrowed) and pull
off the light switch control knob41.21 Withdraw the light switch and
disconnect the wiring plug
41.23 Undo the three retaining screws
(arrowed) to disconnect the right-hand vent41.24 Ashtray retaining screw locations
(arrowed)
procarmanuals.com
The electrical system is a 12 volt, negative
earth type. Electricity is generated by an
alternator, belt-driven from the crankshaft pulley.
A lead-acid battery provides a reserve of power
for starting and when the demands of the system
temporarily exceed the alternator output.
The battery negative terminal is connected
to “earth” - vehicle metal - and most electrical
system components are wired so that they
only receive a positive feed, the current
returning via vehicle metal. This means that
the component mounting forms part of the
circuit. Loose or corroded mountings can
therefore cause apparent electrical faults.
Many semiconductor devices are used in
the electrical system, both in the “black
boxes” which control vehicle functions and in
other components. Semiconductors are very
sensitive to excessive (or wrong polarity)
voltage, and to extremes of heat. Observe the
appropriate precautions to avoid damage.
Although some repair procedures are given
in this Chapter, sometimes renewal of a well-
used item will prove more satisfactory. The
reader whose interests extend beyond
component renewal should obtain a copy of
the “Automobile Electrical Manual”, available
from the publishers of this book.
Before starting work on the electrical
system, read the precautions listed in “Safety
first!” at the beginning of the manual.
Note:Refer to the precautions given in “Safety
first!” and in Section 1 of this Chapter before
starting work. The following tests relate to testing
of the main electrical circuits, and should not be
used to test delicate electronic circuits (such as
anti-lock braking systems), particularly where an
electronic control unit (ECU) is involved.
General
1A typical electrical circuit consists of an
electrical component, any switches, relays,
motors, fuses, fusible links or circuit breakers
related to that component, and the wiring and
connectors which link the component to both
the battery and the chassis. To help to
pinpoint a problem in an electrical circuit,
wiring diagrams are included at the end of this
Chapter.
2Before attempting to diagnose an electrical
fault, first study the appropriate wiring
diagram, to obtain a more complete
understanding of the components included in
the particular circuit concerned. The possible
sources of a fault can be narrowed down by
noting whether other components related to
the circuit are operating properly. If several
components or circuits fail at one time, the
problem is likely to be related to a shared fuse
or earth connection.
3Electrical problems usually stem from
simple causes, such as loose or corroded
connections, a faulty earth connection, a
blown fuse, a melted fusible link, or a faulty
relay. Visually inspect the condition of all
fuses, wires and connections in a problem
circuit before testing the components. Use the
wiring diagrams to determine which terminal
connections will need to be checked in order
to pinpoint the trouble-spot.
4The basic tools required for electrical fault-
finding include: a circuit tester or voltmeter (a
12-volt bulb with a set of test leads can also
be used for certain tests), a self-powered test
light (sometimes known as a continuity tester),
an ohmmeter (to measure resistance), a
battery and set of test leads, and a jumper
wire, preferably with a circuit breaker or fuse
incorporated, which can be used to bypass
suspect wires or electrical components.
Before attempting to locate a problem with
test instruments, use the wiring diagram to
determine where to make the connections.
5To find the source of an intermittent wiring
fault (usually due to a poor or dirty connection,
or damaged wiring insulation), an integrity testcan be performed on the wiring, which
involves moving the wiring by hand, to see if
the fault occurs as the wiring is moved. It
should be possible to narrow down the source
of the fault to a particular section of wiring.
This method of testing can be used in
conjunction with any of the tests described in
the following sub-Sections.
6Apart from problems due to poor
connections, two basic types of fault can
occur in an electrical circuit - open-circuit or
short-circuit.
7Open-circuit faults are caused by a break
somewhere in the circuit, which prevents
current from flowing. An open-circuit fault will
prevent a component from working, but will
not cause the relevant circuit fuse to blow.
8Short-circuit faults are caused by a “short”
somewhere in the circuit, which allows the
current flowing in the circuit to “escape” along
an alternative route, usually to earth. Short-
circuit faults are normally caused by a
breakdown in wiring insulation, which allows a
feed wire to touch either another wire, or an
earthed component such as the bodyshell. A
short-circuit fault will normally cause the
relevant circuit fuse to blow. Note: A short-
circuit that occurs in the wiring between a
circuit’s battery supply and its fuse will not
cause the fuse in that particular circuit to blow.
This part of the circuit is unprotected - bear
this in mind when fault-finding on the vehicle’s
electrical system.
Finding an open-circuit
9To check for an open-circuit, connect one
lead of a circuit tester or voltmeter to either the
negative battery terminal or a known good earth.
10Connect the other lead to a connector in
the circuit being tested, preferably nearest to
the battery or fuse.
11Switch on the circuit, bearing in mind that
some circuits are live only when the ignition
switch is moved to a particular position.
12If voltage is present (indicated either by
the tester bulb lighting or a voltmeter reading,
as applicable), this means that the section of
2Electrical fault-finding - general
information
1General information
Body electrical system 13•3
13
Other relays and modules (continued)
IdentificationFunction
Behind facia (passenger side) (continued):
M4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Heated windscreen (timer)
M5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Air conditioning cooling fan
M6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .ABS pump relay
M7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .ABS main relay
M8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .ABS control unit
M9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Ride height control
Below instrument panel (driver’s side):
N1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Bulb failure warning unit
Below facia (passenger side):
P1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .ABS module
P2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Fuel-injection system module
Behind facia (passenger side):
R1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Speed control system module
R2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Auxiliary warning system module
R3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Rear audio console module
Torque wrench settingsNmlbf ft
Alternator adjusting strap:
To steering pump bracket (SOHC) . . . . . . . . . . . . . . . . . . . . . . . . . . .21 to 2616 to 19
To front cover (V6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41 to 5130 to 38
procarmanuals.com
Heated rear window switch
Models before April 1992
50Remove the instrument panel surround,
which is secured by four screws.
51Carefully prise the switch from its location,
disconnect the multi-plug and remove it.
Models from April 1992
52Using a small flat-bladed screwdriver,
carefully prise the switch out of the centre
facia vent panel and disconnect the wiring
connector.
53On refitting, reconnect the wiring
connector and push the switch in until it clicks
into position.
Foglight switch(es)
54These are removed in the same way as the
heated rear window switch (see illustration).
Hazard warning switch
55This is integral with the direction indicator
switch.
Front seat adjusting switch
56Remove the seat trim panel.
57Prise the operating levers off the switch
with a thin-bladed screwdriver (see
illustration).
58Remove the two securing screws,
withdraw the switch and unplug it.
Rear seat adjusting switch
59This is removed in the same way as the
mirror control switch already described in
paragraphs 10 and 11.
Heated seat control switches
60These are removed in the same way as the
mirror control switch already described in
paragraphs 10 and 11.
Starter inhibitor/reversing light
switch (automatic transmission)
61Refer to Chapter 7 part B.
Fuses
1The battery positive (live) lead is protected
by a fusible link. If this link melts, a major
short-circuit is indicated and expert advice
should be sought before repairing it.
2The main fuse/relay box is located under the
bonnet, near the bulkhead on the right-hand
side. It contains up to 24 fuses and nearly as
many relays (according to equipment). Fuse
applications are listed on the underside of the
fuse box lid (see illustration).
3There is an auxiliary fuse box inside the
vehicle, accessible after opening the glovebox
(see illustration). An in-line fuse for the radio
is located under the facia on the left-hand
side, near the heater.4The“blade” type fuses are colour-coded to
show their current rating. A blown fuse can be
recognised by the melted wire link in the
middle.
5To renew a blown fuse, first switch off the
circuit concerned. Pull the old fuse out of its
holder, using tweezers or long-nosed pliers.
Press in a new fuse of the same rating and try
the circuit again.
6If the new fuse blows immediately or within
a short time, do not carry on renewing fuses
but look for a short-circuit in the wiring to the
item(s) protected by the fuse. When more than
one item is protected by a single fuse,
switching on one item at a time until the fuse
blows will help to isolate the defect.
7Never fit a fuse of a higher rating (current
capacity) than specified, and do not bypass
fuses with silver foil or strands of wire. Serious
damage, including fire, could result.
8In some positions (such as for power
window and seat adjustment motors) circuit
breakers are fitted instead of fuses. These are
normally self-resetting once the cause of the
overload has been cleared.
Relays
9If a circuit or system served by a relay
develops a fault, always remember that the
problem could be in the relay. Testing is by
substitution of a known good unit. Beware of
substituting relays which look the same but
perform different functions(see illustration).10To renew a relay, simply unplug it from its
holder and plug in the new one. Access to the
relays in the main fuse box is as described for
the fuses. Access to the relays located behind
the facia is achieved by removing the facia
top.
11The sliding roof relay is located in the
overhead console.
Control units and modules
12The two major modules are the EEC IV
module (on fuel-injection models) and the ABS
control module. These are located below the
glovebox on the passenger side, and are
accessible after removing the under-dash trim.
13As with relays, testing by the home
mechanic is limited to substitution of known
good units. This is likely to be prohibitively
expensive on a trial and error basis so in case
of problems a Ford dealer or other competent
specialist should be consulted at an early
stage.
1Disconnect the battery negative lead and
unlock all the doors before starting work on
the central locking system. Make sure that the
keys are outside the vehicle before
reconnecting the battery on completion.
2Remove the door interior trim panel.
17Central locking motor -
removal and refitting
16Fuses, relays and control
units - removal and refitting
Body electrical system 13•13
13
15.54 Removing a foglight switch15.57 Removing the front seat adjusting
switch
16.2 Main fuse/relay box under the bonnet16.3 Auxiliary fuse box in the glovebox
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Computer module and bulb
Models before April 1992
2Remove the instrument panel surround,
which is secured by four screws.
3Carefully pull the module from its location.
Release the multi-plug by pressing
downwards and disconnect it.
4The module illumination bulbholder may
now be extracted by gripping it with pliers and
twisting it anti-clockwise (see illustration).
Extract the old wedge base bulb, press in the
new one and refit the bulb and holder.
5Reconnect the multi-plug and press the
module back into its hole. Check for correct
operation, then refit the instrument panel
surround.
Models from April 1992
6Disconnect the battery negative terminal.
7Undo the two instrument cluster surround
retaining screws then release the two retaining
clips and remove the surround. Disconnect the
instrument cluster dimmer switch as it is
removed.
8Pull off the three knobs from the heater and
ventilation controls to gain access to the two
hidden central vent panel retaining screws.
Slacken and remove the four panel retaining
screws and partially withdraw the panel.
Disconnect the wiring connectors from the
heated window switches and fuel computer
and remove the panel from the car.
9Undo the four fuel computer retaining
screws and remove the computer from the
vent panel (see illustration).
10Refitting is a reverse of the removal
procedure.
Fuel flow sensor (carburettor
models only)
11The fuel flow sensor is located under the
bonnet, on the left-hand inner wing (see
illustration).
12Disconnect the battery negative lead.
13Disconnect the multi-plug and the fuel
pipes from the sensor. Be prepared for fuel
spillage; plug or cap the pipes.
14Remove the three screws which secure
the sensor bracket. Remove the sensor and
bracket together; they can be separated on
the bench if wished.15Refit by reversing the removal operations.
Use new fuel pipe clips if the old ones were
damaged during removal.
Note that if a fault develops in the AWS,
thorough testing and fault finding should be
left to a Ford dealer or other competent
specialist. Unskilled or uninformed testing may
cause further damage. When checking wires
or sensors for continuity, disconnect the
control assembly and bulb failure module first,
otherwise damage may be caused.
Warning light bulbs
1Refer to Sections 7 and 8.
Graphic display module
2Refer to Sections 7 and 8.
3The bulbs and light emitting diodes (LEDs)
can be removed from the module using
tweezers or jeweller’s pliers. When renewing
the fuel filler warning LED, note that the pip on
the LED must align with the yellow dot on the
circuit board.
Fuel filler switch
4Open the fuel filler flap and remove the cap.
5Inside the luggage area, remove the trim on
the right-hand side and disconnect the switch
multi-plug(see illustration).6Remove the screw which secures the switch
to the filler neck. Remove the switch and
withdraw its wires.
7Refit by reversing the removal operations.
Air temperature sensor
8From under the front bumper, unclip and
disconnect the sensor multi-plug.
9Unclip the sensor from its slot by pulling the
securing tag inwards. Remove the sensor (see
illustration).
10When refitting, first connect the multi-plug.
Fit the hook on the end of the sensor into the
slot and press the sensor into place, then
secure the multi-plug in its clip.
Door/tailgate switch
11Remove the door interior ortailgate
interior trim panel (eleven screws).
12Pull the switch to detach it from the lock
and disconnect its multi-plug.
13Refit by reversing the removal operations.
Coolant level switch
14Remove the cap from the coolant
expansion tank, taking precautions against
scalding if the coolant is hot.
15Syphon coolant out of the tank if
necessary until the level is below the switch.
16Disconnect the switch multi-plug.
Unscrew the retaining ring and pull the switch
out of its grommet. Note how flats on the
grommet and switch ensure correct fitting
(see illustration).
27Auxiliary warning system
components - testing, removal
and refitting
13•18Body electrical system
26.4 Renewing the fuel computer module
bulb
27.5 Fuel filler switch screw (arrowed)27.9 Removing the air temperature sensor
26.9 Fuel computer retaining screws
(arrowed)26.11 Fuel flow sensor fitted to carburettor
models
procarmanuals.com
WD•0
Explanatory notes for wiring diagrams
Each wiring diagram covers a particular system of the vehicle; as indicated in each caption. When a number is shown on a diagram inside a box
with an arrow symbol, this indicates that the circuit concerned starts, or is continued, in the diagram having that number.
Space limitations mean that not all diagrams have been included. Therefore the diagram numbers are not consecutive, neither is it always
possible to follow a particular circuit to completion. Some diagrams are out of sequence; this is to ensure that the halves of the larger diagrams
appear on opposite pages.
The prefix C indicates a connector or multi-plug, S a soldered joint and G an earthing point (ground). The numbers appearing at the break in
each wire indicate the circuit number and wire colour.
Colour code
BLBlue
BRBrown
GEYellow
GRGrey
GNGreen
RSPink
RT Red
SWBlack
VIViolet
WSWhiteSubjectDiagram number
ABS21
Auxiliary warning system23
Central locking system14
Charge, start and run3
Charge, start and run3A
Engine management (1.8 litre)4
Engine management (2.0 litre carburettor)4A
Engine management (2.0 litre fuel-injection)5
Engine management (2.8 litre)5C
Exterior lighting7A
Heater blower11
Interior lighting10
Power 0perated windows15
Power distribution2
Power-operated sliding roof16
Radio/cassette player and associated circuits29
Signalling and warning systems9
Wipers and washers12
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REF•6
Engine fails to rotate when attempting to start
m mBattery terminal connections loose or corroded (Chapter 1).
m mBattery discharged or faulty (Chapter 5).
m mBroken, loose or disconnected wiring in the starting circuit
(Chapter 5).
m mDefective starter solenoid or switch (Chapter 5).
m mDefective starter motor (Chapter 5).
m mStarter pinion or flywheel/driveplate ring gear teeth loose or broken
(Chapters 2 or 5).
m mEngine earth strap broken or disconnected.
Starter motor turns engine slowly
m
mPartially-discharged battery (recharge, use jump leads, or push
start) (Chapter 5).
m mBattery terminals loose or corroded (Chapter 1).
m mBattery earth to body defective (Chapter 5).
m mEngine earth strap loose.
m mStarter motor (or solenoid) wiring loose (Chapter 5).
m mStarter motor internal fault (Chapter 5).
Engine rotates, but will not start
m
mFuel pump inertia switch tripped (electric pump) (Chapter 4).
m mFuel tank empty.
m mBattery discharged (engine rotates slowly) (Chapter 5).
m mBattery terminal connections loose or corroded (Chapter 1).
m mIgnition components damp or damaged (Chapters 1 and 5).
m mBroken, loose or disconnected wiring in the ignition circuit
(Chapters 1 and 5).
m mWorn, faulty or incorrectly-gapped spark plugs (Chapter 1).
m mFuel injection system fault (Chapter 4).
m mMajor mechanical failure (eg broken timing chain) (Chapter 2).
Engine difficult to start when cold
m
mBattery discharged (Chapter 5).
m mBattery terminal connections loose or corroded (Chapter 1).
m mWorn, faulty or incorrectly-gapped spark plugs (Chapter 1).
m mFuel injection system fault (Chapter 4).
m mOther ignition system fault (Chapters 1 and 5).
m mLow cylinder compressions (Chapter 2).
Engine difficult to start when hot
m
mAir filter element dirty or clogged (Chapter 1).
m mFuel injection system fault (Chapter 4).
m mLow cylinder compressions (Chapter 2).
Starter motor noisy or excessively-rough in
engagement
m mStarter pinion or flywheel/driveplate ring gear teeth loose or broken
(Chapters 2 or 5).
m mStarter motor mounting bolts loose or missing (Chapter 5).
m mStarter motor internal components worn or damaged (Chapter 5).
Engine starts, but stops immediately
m
mLoose or faulty electrical connections in the ignition circuit
(Chapters 1 and 5).
m mVacuum leak at the throttle body or inlet manifold (Chapter 4).
m mFuel injection system fault (Chapter 4).
Engine idles erratically
m
mCarburettor stepper motor plunger dirty (2.0 litre only) (Chapter 5)
m mIncorrectly-adjusted idle speed (Chapter 4).
m mAir filter element clogged (Chapter 1).
m mVacuum leak at the throttle body, inlet manifold or associated hoses
(Chapter 4).
m mWorn, faulty or incorrectly-gapped spark plugs (Chapter 1).
m mUneven or low cylinder compressions (Chapter 2).
m mCamshaft lobes worn (Chapter 2).
m mFuel injection system fault (Chapter 4).
Engine misfires at idle speed
m
mWorn, faulty or incorrectly-gapped spark plugs (Chapter 1).
m mFaulty spark plug HT leads (Chapter 5).
m mVacuum leak at the throttle body, inlet manifold or associated hoses
(Chapter 4).
m mFuel injection system fault (Chapter 4).
m mDistributor cap cracked or tracking internally, where applicable
(Chapter 5).
m mUneven or low cylinder compressions (Chapter 2).
m mDisconnected, leaking, or perished crankcase ventilation hoses
(Chapter 4).
Fault Finding
spark plugs may only be pointers to some underlying fault.
The pages which follow provide an easy-reference guide to the more
common problems which may occur during the operation of the
vehicle. These problems and their possible causes are grouped under
headings denoting various components or systems, such as Engine,
Cooling system, etc. The Chapter and/or Section which deals with the
problem is also shown in brackets. Whatever the fault, certain basic
principles apply. These are as follows:
Verify the fault. This is simply a matter of being sure that you know
what the symptoms are before starting work. This is particularly
important if you are investigating a fault for someone else, who may
not have described it very accurately.
Don’t overlook the obvious. For example, if the vehicle won’t start, is
there fuel in the tank? (Don’t take anyone else’s word on this particular
point, and don’t trust the fuel gauge either!) If an electrical fault isindicated, look for loose or broken wires before digging out the test
gear.
Cure the disease, not the symptom. Substituting a flat battery with a
fully-charged one will get you off the hard shoulder, but if the
underlying cause is not attended to, the new battery will go the same
way. Similarly, changing oil-fouled spark plugs for a new set will get
you moving again, but remember that the reason for the fouling (if it
wasn’t simply an incorrect grade of plug) will have to be established
and corrected.
Don’t take anything for granted. Particularly, don’t forget that a
“new” component may itself be defective (especially if it’s been rattling
around in the boot for months), and don’t leave components out of a
fault diagnosis sequence just because they are new or recently-fitted.
When you do finally diagnose a difficult fault, you’ll probably realise
that all the evidence was there from the start.
1 Engine
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