1988 OPEL VECTRA ignition

3Air cleaner - removal and
refitting
2
Removal
1Remove the air cleaner element, as
described in Chapter 1.
2Release the crankcase ventilation hose
from the plastic clip on the left-hand side of
the air cleaner body.
3Disconnect the inlet duct from the hot air
hose on the exhaust manifold (see
illustration), and lift the air cleaner body from
the carburettor.
4With the body tilted to the rear, disconnect
the crankcase ventilation hose from the stub
on the underside of the body (see
illustration).Where applicable, disconnect
the vacuum hose from the air temperature
control flap thermostat.
5Remove the seal from under the air cleaner
body.
Refitting
6Check the hot air hose for condition, and
renew it if necessary.
7Fit a new air cleaner body-to-carburettor
seal.
8Connect the crankcase ventilation hose to
the stub on the underside of the body, and
connect the vacuum hose for the air
temperature control flap.
9Locate the body on the carburettor, and at
the same time locate the inlet duct on the hot
air hose on the exhaust manifold.
10Engage the crankshaft ventilation hose in
the plastic clip.
11Refit the air cleaner element, referring to
Chapter 1 if necessary.
4Air cleaner inlet air
temperature control -
description and testing
3
Description
1The air cleaner is thermostatically-
controlled, to provide air at the most suitable
temperature for combustion with minimum
exhaust emission levels.
2The optimum air temperature is achieved
by drawing in cold air from an inlet at the front
of the vehicle, and blending it with hot airdrawn from a shroud on the exhaust manifold.
The proportion of hot and cold air is varied by
the position of a flap valve in the air cleaner
inlet spout, which is controlled by either a
vacuum diaphragm or wax-type unit. The
vacuum diaphragm type is regulated by a heat
sensor located within the air cleaner body
(see illustration).
Testing
3To check the operation of the air
temperature control, the engine must be cold.
First check the position of the flap valve. On
the vacuum type, remove the air cleaner cover
and check that the flap is open to admit only
cold air from outside the car. Then start the
engine and check that the flap now moves to
admit only hot air from the exhaust manifold.
On the wax type, the flap should already be
positioned to admit only hot air from the
exhaust manifold.
4Temporarily refit the cover on the vacuum
type.
5Run the engine until it reaches its normal
operating temperature.
6On the vacuum type, remove the air cleaner
cover and check that the flap is now
positioned to admit only cold air from outside
the car. In cold weather it should be a mixture
of hot and cold air. Refit the cover after
making the check. On the wax type, use a
mirror to check that the flap is positioned in
the same way as given for the vacuum type.
7If the flap does not function correctly, the
air cleaner casing must be renewed. Note that
the vacuum type thermostat can be renewed
separately if necessary.
5Fuel pump - testing
2
Note: Refer to Section 2 before proceeding
1Disconnect the ignition coil LT lead.
2Place a clean piece of rag under the pump
outlet, then disconnect the pump outlet hose.
Be prepared for fuel spillage, and take
adequate fire precautions.
3Have an assistant crank the engine on the
starter. Well-defined spurts of fuel must be
ejected from the pump outlet - if not, the
pump is probably faulty (or the tank is empty).
Dispose of the fuel-soaked rag safely.
4No spare parts are available for the pump,
and if faulty, the unit must be renewed.
6Fuel pump - removal and
refitting
3
Note: Refer to Section 2 before proceeding
Removal
1The fuel pump is located at the rear right-
hand end of the camshaft housing.
2Disconnect the battery negative lead.
3Disconnect the fuel hoses from the pump
(see illustration). If necessary, label the
hoses so that they can be reconnected to
their correct locations. Be prepared for fuel
spillage, and take adequate fire precautions.
Plug the open ends of the hoses to prevent
dirt ingress and further fuel spillage.
Fuel and exhaust systems - carburettor models 4A•3
3.4 Disconnecting the crankcase
ventilation hose (arrowed)
6.3 Disconnecting a fuel hose from the
fuel pump - 1.6 litre model4.2 Air cleaner flap valve operating
mechanism
1 Flap valve 2 Operating rod
3.3 The air cleaner body locates over the
hot air hose
4A
Warning: Many of the
procedures given in this
Chapter involve the
disconnection of fuel pipes and
system components, which may result in
some fuel spillage. Before carrying out
any operation on the fuel system, refer to
the precautions given in the “Safety first!”
Section at the beginning of this manual
and follow them implicitly. Petrol is a
highly dangerous and volatile substance,
and the precautions necessary when
handling it cannot be overstressed.

2A separate idle system operates
independently from the main jet system,
supplying fuel by way of the mixture control
screw.
3The main jets are calibrated to suit engine
requirements at mid-range throttle openings.
To provide the necessary fuel enrichment at
full throttle, a vacuum-operated power valve is
used. The valve provides extra fuel under the
low vacuum conditions associated with wide
throttle openings.
4To provide an enriched mixture during
acceleration, an accelerator pump delivers
extra fuel to the primary main venturi. The
accelerator pump is operated mechanically by
a cam on the throttle linkage.
5A fully automatic choke is fitted, operated
by a coolant and electrically heated bi-metal
coil. When the engine is cold, the bi-metal coil
is fully wound up, holding the choke plate
(fitted to the primary barrel) closed. As the
engine warms up, the bi-metal coil is heated
and therefore unwinds, progressively opening
the choke plate. A vacuum operated pull-
down system is employed, whereby, if the
engine is under choke but is only cruising (i.e.
not under heavy load) the choke plate is
opened against the action of the bi-metal coil.
The pull-down system prevents an over-rich
mixture, which reduces fuel economy and
may cause unnecessary engine wear when
the engine is cold. A secondary pull-down
solenoid is fitted, which operates in
conjunction with the main diaphragm unit to
modify the pull-down characteristics,
improving fuel economy.
61.8 litre models are fitted with an idle cut-off
solenoid. This is an electrically operated valve,
which interrupts the idle mixture circuit when
the ignition is switched off, this preventing
engine “run-on”.13Carburettor - removal,
overhaul and refitting
3
Note: Refer to Section 2 before proceeding.
New gasket(s) must be used when refitting the
carburettor. A tachometer and an exhaust gas
analyser will be required to check the idle
speed and mixture on completion
Removal
1Disconnect the battery negative lead.
2Remove the air cleaner, on early models.
On later models, disconnect the air trunking
from the air cleaner, then disconnect the
vacuum pipe and breather hose from the air
box. Extract the three securing screws and lift
off the air box, complete with air trunking.
3On 1.4 litre models, disconnect the fuel
supply hose from the carburettor, and on 1.6
and 1.8 litre models, disconnect the fuel
supply and return hoses from the vapour
separator. Be prepared for fuel spillage, and
take adequate fire precautions. Plug the ends
of the hoses, to prevent dirt ingress and
further fuel spillage.
4Extract the clip from the throttle cable end
fitting at the bracket on the carburettor, then
slide the cable end grommet from the bracket,
and slide the cable end from the throttle valve
lever.
5Disconnect the coolant hoses from the
automatic choke housing noting their
locations, as an aid to refitting. Be prepared
for coolant spillage, and plug the hoses, or
secure them with their ends facing upwards,
to prevent further coolant loss.
6Disconnect the vacuum pipes from the front
of the carburettor, noting their locations and
routing for use when refitting (see
illustration).
7Disconnect the choke heater wire and any
additional wiring.8Unscrew the three securing nuts, and
withdraw the carburettor from the inlet
manifold studs.
9Recover the gasket(s) and insulator block
that fit between the carburettor and the inlet
manifold.
Overhaul
10With the carburettor removed from the
vehicle, drain the fuel from the float chamber
and vapour separator (where applicable).
Clean the outside of the carburettor, then
remove the top cover (Section 15).
11Blow through the jets and drillings with
compressed air, or air from a foot pump - do
not probe them with wire. If it is wished to
remove the jets, unscrew them carefully with
well-fitting tools.
12Remove the fuel filter gauze from the inlet
union, refer to Section 21, for details. Vauxhall
recommend that it is renewed whenever the
carburettor is cleaned.
4A•6Fuel and exhaust systems - carburettor models
12.1B Side view of carburettor, showing automatic choke
housing (1), vapour separator (2) and secondary throttle valve
vacuum diaphragm (3)12.1C Side view of carburettor, showing secondary choke pull-
down solenoid (1) and power valve (2)
13.6 Disconnecting the air box vacuum
pipe from the carburettor - 1.6 litre model
Aerosol cans of carburettor
cleaner are widely available
and can prove useful in
helping to clean internal
passages of stubborn obstructions.

13Clean any foreign matter from the float
chamber. Renew the float, the float needle
valve and seat if wear is evident, or if the float
is punctured or otherwise damaged. Check
that the needle valve closes completely before
the float reaches the top of its movement. See
Section 15, for details of float level checking.
14Renew the diaphragms in the part-load
enrichment valve and in the accelerator pump.
If additional pump or valve parts are supplied
in the overhaul kit, renew these parts also.
15Further dismantling is not recommended.
Pay particular attention to the throttle opening
mechanism arrangement if it is decided to
dismantle it; the interlocking arrangement is
important.
16Reassemble in the reverse order to
dismantling. Use new gaskets and seals
throughout; lubricate linkages with a smear of
molybdenum based grease.
Refitting
17Carry out the following procedure before
refitting.
a)Position the fast idle adjustment screw on
the highest step of the fast idle cam.
b)Use a gauge rod or twist drill of the
specified diameter to measure the
opening of the primary throttle valve.
c)Adjust if necessary at the fast idle
adjustment screw.
d)Note that this is a preliminary adjustment;
final adjustment of the fast idle speed
should take place with the engine running.
18Refitting is a reversal of removal, but
renew the gasket(s).
19After refitting, carry out the following
checks and adjustments.
20Check the throttle cable free play and
adjust if necessary, as described in Section 11.
21Check and if necessary top-up the
coolant level, as described in Chapter 3.
22Check and if necessary adjust the idle
speed and mixture, as described in Section 14.
14Idle speed and mixture -
adjustment
3
Note: Refer to Section 2 before proceeding.
To carry out the adjustments, an accurate
tachometer and an exhaust gas analyser (CO
meter) will be required
1To check the idle speed and mixture
adjustment, the following conditions must be
met:
a)The engine must be at normal operating
temperature
b)All electrical consumers (cooling fan,
heater blower, headlamps, etc.) must be
switched off
c)The ignition timing and spark plug gaps
must be correctly adjusted - see Chapters
1 and 5
d)The throttle cable free play must be
correctly adjusted - see Section 11
e)The air inlet trunking must be free from
leaks, and the air filter must be cleanf)On automatic models, always select
position, “P”.
2Connect a tachometer and an exhaust gas
analyser to the vehicle, according to the
equipment manufacturer’s instructions.
3Start the engine, and run it at 2000 rpm for
approximately 30 seconds, then allow it to
idle. If the idle speed is outside the specified
limits, adjust by means of the throttle stop
screw (see illustration).
4When the idle speed is correct, check the
CO level in the exhaust gas. If it is outside the
specified limits, adjust by means of the idle
mixture adjustment screw. In production, the
screw is covered by a tamperproof plug;
ensure that no local or national laws are being
broken before removing the plug (see
illustration).
5On automatic models, when position “D” is
selected (all electrical systems switched off),
the idle speed should not drop perceptibly. If
it does, the vehicle should be taken to a
Vauxhall dealer for the idle-up system to be
checked using special Vauxhall test
equipment.
6With the idle mixture correct, readjust the
idle speed if necessary.
7If the cooling fan cuts in during the
adjustment procedure, stop the adjustments,
and continue when the cooling fan stops.
8When both idle speed and mixture are
correctly set, stop the engine and disconnect
the test equipment.
9Fit a new tamperproof plug to the idle
mixture adjustment screw, where this is
required by law.
15Needle valve and float -
removal, inspection and
refitting
4
Note: Refer to Section 2 before proceeding. A
new carburettor top cover gasket must be
used on reassembly. A tachometer and an
exhaust gas analyser will be required to check
the idle speed and mixture on completion
Removal
1Disconnect the battery negative lead.
2Remove the round air cleaner, on
applicable models. On other models,
disconnect the air trunking from the air
cleaner, then disconnect the vacuum pipe and
breather hose from the air box. Extract the
three securing screws and lift off the air box,
complete with air trunking.
3Thoroughly clean all external dirt from the
carburettor.
4Disconnect the fuel supply hose at the
carburettor. Be prepared for fuel spillage, and
take adequate fire precautions. Plug the end
of the hose, to prevent dirt ingress and further
fuel spillage.
5Identify the automatic choke coolant hose
locations as an aid to refitting, then
disconnect the hoses. Be prepared for
coolant spillage, and either plug the hoses, or
secure them with their ends facing upwards,
to prevent further coolant loss.
6Disconnect the choke heater wiring plug.
7Disconnect the lower vacuum hoses from
the choke pull-down unit.
8Remove the four carburettor top cover
securing screws, noting their locations, as two
lengths of screw are used (see illustration).
9Lift off the top cover and recover the
gasket.
Inspection
10Hold the cover vertically, so that the float
is hanging from its pivot. Then tilt the cover
until the float needle valve is just closed - the
needle spring must not be compressed by the
weight of the float.
11Measure the distance, dimension x (see
illustration),from the bottom of the float to
the gasket surface on the top cover’s
Fuel and exhaust systems - carburettor models 4A•7
15.8 Carburettor top cover securing
screws (arrowed)14.4 Tamperproof plug (arrowed) covering
idle mixture adjustment screw
14.3 Carburettor idle speed adjustment
(throttle stop) screw (arrowed)
4A

Refitting
6On refitting the filter, press it into the union
until it catches (see illustration). The
remainder of the reassembly procedure is the
reverse of removal.
22Throttle valve dashpot
(automatic models) -
adjustment
2
1Remove the air cleaner or air box, refer to
Section 3.
2Ensure that the lever (see illustration)is in
the idling position.
3Slacken the locknut and unscrew the
dashpot until a gap of 0.05 mm (0.002 in)
exists between the lever and the dashpot tip.
Then screw the dashpot downwards 2.5 full
turns and tighten the locknut.
4Refit all removed components.
23Throttle position sensor
(automatic transmission
models) - removal and refitting
2
Removal
1Disconnect the battery earth lead.
2Disconnect the wiring plug from the sensor.
3Either unscrew the two securing screws
and withdraw the sensor from its bracket, or
unbolt the bracket.
Refitting
4Refitting is the reverse of the removal
procedure, noting the following points.
a)Install the sensor when the throttle valve
is fully closed and ensure that the
adapter, “1” (see illustration),seats
correctly on the throttle valve spindle.
b)Tighten the screws carefully.
24Idle speed increase valve -
testing
2
1Certain models are fitted with an idle speed
increase valve that is attached to the side of
the carburettor.
2To test the operation of this valve first
remove the air filter and vacuum hose.
3With the valve’s plug connected, have
someone turn the ignition on (but do not start
the engine). A mechanical shifting noise
should be heard. If not replace the unit.
4After refitting replace the vacuum hose and
air filter.
25Idle cut-off solenoid (1.8 litre
models) - description and
testing
2
Note: Refer to Section 2 before proceeding
Description
1On 1.8 litre models, the carburettor is fitted
with an idle cut-off solenoid. This is an
electrically operated valve, which interrupts
the idle mixture circuit when the ignition isswitched off, thus preventing the engine from
running-on (see illustration).
2The idle cut-off solenoid is energised all the
time that the ignition is switched on. A
defective solenoid, or a break in its power
supply, will cause the engine to stall or idle
roughly, although it will run normally at speed.
Testing
3If the operation of the solenoid is suspect,
first check that battery voltage is present at
the solenoid terminal when the ignition is
switched on. Use a 12 volt test lamp or similar
test device.
4If no voltage is present, then the fault lies in
the wiring to the solenoid. If voltage is
present, the solenoid can be tested as
follows.
5With the solenoid unscrewed from the
carburettor, connect the body of the solenoid
to the negative terminal of a 12 volt battery.
When the battery positive terminal is
connected to the solenoid centre terminal,
there should be an audible click, and the
needle at the tip of the solenoid should
retract.
6A defective idle cut-off solenoid must be
renewed.
26Inlet manifold - removal and
refitting
3
Note: Refer to Section 2 before proceeding. A
new manifold gasket must be used on refitting
Removal
1Disconnect the battery negative lead.
2Drain the cooling system, as described in
Chapter 3.
3Proceed as described in Section 13,
paragraphs 2 to 7 inclusive, ignoring the
reference to coolant spillage in paragraph 5.
4A•12Fuel and exhaust systems - carburettor models
21.6 Refitting the carburettor fuel filter
23.4 Throttle position sensor - models with automatic
transmission
1 Adapter 2 Sensor22.2 Adjusting the throttle valve dashpot - models with
automatic transmission
1 Lever2 Locknut3 Dashpot

12
Wiper blades
Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 ins. Champion X-4803
Fuses
Rating:
Red . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 A
Blue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 A
Yellow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 A
Green . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 A
Torque wrench settingsNm lbf ft
Airbag unit to steering wheel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 7
Airbag control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 7
Brackets, passenger airbag . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 16
Passenger airbag to bracket . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 6
Steering to column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 18
Chapter 12
Body electrical systems
Aerial - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47
Aerial mast, electric - removal and refitting . . . . . . . . . . . . . . . . . . . .48
Airbag - general . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55
Airbag contact unit - removal and refitting . . . . . . . . . . . . . . . . . . . . .58
Airbag control unit - removal and refitting . . . . . . . . . . . . . . . . . . . . .61
Airbag unit, drivers side - removal and refitting . . . . . . . . . . . . . . . . .56
Airbag unit, passengers side - removal and refitting . . . . . . . . . . . . .59
Anti-theft alarm - general . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53
Anti-theft alarm system components - removal and refitting . . . . . . .54
Bracket, passenger airbag unit - removal and refitting . . . . . . . . . . .60
Brake lamp switch - removal and refitting . . . . . . . . . . . . . . . . . . . . .12
Central door locking components - removal and refitting . . . . . . . . .46
Check control system components - removal and refitting . . . . . . . .21
Cigarette lighter - removal and refitting . . . . . . . . . . . . . . . . . . . . . . .15
Clock - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Courtesy lamp switch - removal and refitting . . . . . . . . . . . . . . . . . . .10
Direction indicator/lighting switch - removal and refitting . . . . . . . . . .5
Electric door mirror switch - removal and refitting . . . . . . . . . . . . . . . .8
Electric window components - removal and refitting . . . . . . . . . . . . .44
Electric window controls - programming . . . . . . . . . . . . . . . . . . . . . .45
Electrical fault-finding - general information . . . . . . . . . . . . . . . . . . . . .2
Exterior lamp bulbs - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
Facia panel switches - removal and refitting . . . . . . . . . . . . . . . . . . . .7
Front indicator lamp unit - removal and refitting . . . . . . . . . . . . . . . .29
Front foglamp - removal, refitting and adjustment . . . . . . . . . . . . . . .31
Fuses and relays - general . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
General information and precautions . . . . . . . . . . . . . . . . . . . . . . . . . .1
Handbrake “on” warning lamp switch - removal and refitting . . . . . .13
Headlamp aim adjustment motor - removal and refitting . . . . . . . . . .26
Headlamp dim-dip system - general, removal and refitting . . . . . . . .28
Headlamp unit - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . .25
Headlamp washer fluid non-return valve - removal and refitting . . . .43Headlamp wiper motor - removal and refitting . . . . . . . . . . . . . . . . . .40
Headlamps - alignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
Heated front seats - general . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
Horn(s) - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
Ignition switch and lock cylinder - removal and refitting . . . . . . . . . . .4
Instrument panel - removal and refitting . . . . . . . . . . . . . . . . . . . . . .18
Instrument panel components - removal and refitting . . . . . . . . . . . .19
Interior lamp bulbs - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
Interior lamps - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . .23
Luggage compartment lamp switch - removal and refitting . . . . . . .11
Number plate lamp - removal and refitting . . . . . . . . . . . . . . . . . . . . .33
Oil pressure warning lamp switch - removal and refitting . . . . . . . . .14
Radio/cassette player - removal and refitting . . . . . . . . . . . . . . . . . . .50
Rear lamp unit - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . .32
Reversing lamp switch . . . . . . . . . . . . . . . . . . . . . . . . .See Chapter 7A
Side repeater lamp - removal and refitting . . . . . . . . . . . . . . . . . . . . .30
Speakers - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . .49
Speedometer cable - removal and refitting . . . . . . . . . . . . . . . . . . . .52
Steering wheel (with airbag) - removal and refitting . . . . . . . . . . . . . .57
Sunroof motor - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . .51
Sunroof operating switch - removal and refitting . . . . . . . . . . . . . . . . .9
Tailgate wiper motor - removal and refitting . . . . . . . . . . . . . . . . . . . .39
Trip computer components - removal and refitting . . . . . . . . . . . . . .20
Wash/wipe switch - removal and refitting . . . . . . . . . . . . . . . . . . . . . .6
Washer fluid reservoir - removal and refitting . . . . . . . . . . . . . . . . . . .41
Washer nozzles - removal and refitting . . . . . . . . . . . . . . . . . . . . . . .37
Washer pump - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . .42
Windscreen wiper motor and linkage - removal and refitting . . . . . . .38
Wiper arms - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . .36
Wiper blades - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
Wiring diagrams - general . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62
12•1
Specifications Contents
Easy,suitable for
novice with little
experienceFairly easy,suitable
for beginner with
some experienceFairly difficult,
suitable for competent
DIY mechanic
Difficult,suitable for
experienced DIY
mechanicVery difficult,
suitable for expert DIY
or professional
Degrees of difficulty
54321

1General information and
precautions
The electrical system is of 12-volt negative
earth type. Power for the lights and all
electrical accessories is supplied by a
lead/acid type battery, which is charged by
the alternator.
This Chapter covers repair and service
procedures for the various electrical
components not associated with engine.
Information on the battery, alternator and
starter motor can be found in Chapter 5.
It should be noted that, before working on
any component in the electrical system, the
battery negative terminal should first be
disconnected, to prevent the possibility of
electrical short-circuits and/or fires.
Whenever the occasion arises, carefully
check the routing of the wiring harness,
ensuring that it is correctly secured by the
clips or ties provided so that it cannot chafe
against other components. Carefully check
points such as the clutch cable bracket,
clutch housing and harness support bracket,
the inlet manifold, the horn mounting bracket,
the starter motor terminals, and the rear
bumper and number plate lamp.
If evidence is found of the harness having
chafed against other components, repair the
damage and ensure that the harness is
secured or protected so that the problem
cannot occur again.
2Electrical fault-finding -
general information
Note:Refer to the precautions given in “Safety
first!” (at the beginning of this manual) and to
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 module is used.
A 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 that link the component to boththe battery and the chassis. To help to
pinpoint a problem in an electrical circuit,
wiring diagrams are included at the end of this
Chapter.
Before attempting to diagnose an electrical
fault, first study the appropriate wiring
diagram, to obtain a 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.
Electrical 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 (refer to Section 3 for details of testing
relays). 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,
to pinpoint the trouble-spot.
The basic tools required for electrical fault-
finding include the following:
a)a circuit tester or voltmeter (a 12-volt bulb
with a set of test leads can also be used
for certain tests).
b)a self-powered test light (sometimes
known as a continuity tester).
c)an ohmmeter (to measure resistance).
d)a battery.
e)a set of test leads.
f)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.
To find the source of an intermittent wiring
fault (usually due to a poor or dirty
connection, or damaged wiring insulation), a
“wiggle” test can be performed on the wiring.
This involves wiggling 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.
Apart from problems due to poor
connections, two basic types of fault can
occur in an electrical circuit - open-circuit, or
short-circuit.
Open-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.
Short-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 abreakdown 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.
Finding an open-circuit
To 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.
Connect the other lead to a connector in
the circuit being tested, preferably nearest to
the battery or fuse.
Switch on the circuit, remembering that
some circuits are live only when the ignition
switch is moved to a particular position.
If voltage is present (indicated either by the
tester bulb lighting or a voltmeter reading, as
applicable), this means that the section of the
circuit between the relevant connector and
the battery is problem-free.
Continue to check the remainder of the
circuit in the same fashion.
When a point is reached at which no
voltage is present, the problem must lie
between that point and the previous test point
with voltage. Most problems can be traced to
a broken, corroded or loose connection.
Finding a short-circuit
To check for a short-circuit, first disconnect
the load(s) from the circuit (loads are the
components that draw current from a circuit,
such as bulbs, motors, heating elements, etc.).
Remove the relevant fuse from the circuit,
and connect a circuit tester or voltmeter to the
fuse connections.
Switch on the circuit, remembering that
some circuits are live only when the ignition
switch is moved to a particular position.
If voltage is present (indicated either by the
tester bulb lighting or a voltmeter reading, as
applicable), this means that there is a short-
circuit.
If no voltage is present, but the fuse still
blows with the load(s) connected, this indicates
an internal fault in the load(s).
Finding an earth fault
The battery negative terminal is connected
to “earth” (the metal of the
engine/transmission and the car body), and
most systems are wired so that they only
receive a positive feed. The current returning
through the metal of the car body. This means
that the component mounting and the body
form part of that circuit. Loose or corroded
mountings can therefore cause a range of
electrical faults, ranging from total failure of a
circuit, to a puzzling partial fault. In particular,
lights may shine dimly (especially when
another circuit sharing the same earth point is
in operation). Motors (e.g. wiper motors or the
radiator cooling fan motor) may run slowly,
and the operation of one circuit may have an
affect on another. Note that on many vehicles,
earth straps are used between certain
components, such as the engine/transmission
and the body, usually where there is no metal-
12•2Body electrical systems
Warning: Before carrying out
any work on the electrical
system, read through the
precautions given in “Safety
first!” at the beginning of this manual, and
in Chapter 5.
Caution:If the radio/cassette player fitted
to the vehicle is one with an anti-theft
security code, as the standard unit is, refer
to “Radio/cassette player anti-theft system
- precaution”in the Reference Section of
this manual before disconnecting the
battery.

to-metal contact between components, due
to flexible rubber mountings, etc.
To check whether a component is properly
earthed, disconnect the battery, and connect
one lead of an ohmmeter to a known good
earth point. Connect the other lead to the wire
or earth connection being tested. The
resistance reading should be zero; if not,
check the connection as follows.
If an earth connection is thought to be
faulty, dismantle the connection, and clean
back to bare metal both the bodyshell and the
wire terminal or the component earth
connection mating surface. Be careful to
remove all traces of dirt and corrosion, then
use a knife to trim away any paint, so that a
clean metal-to-metal joint is made. On
reassembly, tighten the joint fasteners
securely; if a wire terminal is being refitted,
use serrated washers between the terminal
and the bodyshell, to ensure a clean and
secure connection. When the connection is
remade, prevent the onset of corrosion in the
future by applying a coat of petroleum jelly or
silicone-based grease.
3Fuses and relays - general
Fuses
1Fuses are designed to break a circuit when
a predetermined current is reached, to protect
the components and wiring which could be
damaged by excessive current flow. Any
excessive current flow will be due to a fault in
the circuit, usually a short-circuit (Section 2).
2The main fuses and relays are located in a
panel at the lower right-hand side of the facia,
under a hinged cover (see illustration).
3The circuits protected by the various fuses
and relays are marked on the inside of the
panel cover.
4A blown fuse can be recognised from its
melted or broken wire.
5To remove a fuse, first ensure that the
relevant circuit is switched off. Then open the
cover and pull the relevant fuse or relay from the
panel (see illustration). If desired, the lower
end of the panel can be tilted forwards, after
releasing the retaining clips to improve access. 6Before renewing a blown fuse, trace and
rectify the cause, and always use a fuse of the
correct rating. Never substitute a fuse of a
higher rating, or make temporary repairs using
wire or metal foil, as more serious damage or
even fire could result.
7Spare fuses are provided in the blank
terminal positions in the fusebox.
8Note that the fuses are colour-coded, see
Specifications. Refer to the wiring diagrams
for details of the fuse ratings and the circuits
protected.
Relays
9A relay is an electrically operated switch,
which is used for the following reasons:
a)A relay can switch a heavy current
remotely from the circuit in which the
current is flowing, allowing the use of
lighter-gauge wiring and switch contacts.
b)A relay can receive more than one control
input, unlike a mechanical switch.
c)A relay can have a timer function - for
example, the intermittent wiper relay.
10Most of the relays are located at the rear
of the main fusebox (remove the securing
screws and pull the fusebox forwards to
improve access). The rear wiper motor relay is
located in the tailgate, behind the tailgate trim
panel. On some models, additional engine-
related relays are located in the relay box
mounted on the left-hand side of the engine
compartment.
11On certain models, additional relays are
located in a box at the left-hand rear of the
engine compartment (see illustration).
12If a circuit or system controlled by a relay
develops a fault, and the relay is suspect,
operate the system. If the relay is functioning, it
should be possible to hear it “click” as it is
energised. If this is the case, the fault lies with
the components or wiring of the system. If the
relay is not being energised, then either the
relay is not receiving a main supply or a
switching voltage, or the relay itself is faulty.
Testing is by the substitution of a known good
unit, but be careful - while some relays are
identical in appearance and in operation, others
look similar but perform different functions.
13To remove a relay, first ensure that the
relevant circuit is switched off. The relay can
then simply be pulled out from the socket,
and pushed back into position.
4Ignition switch and lock
cylinder - removal and
refitting
3
Removal
1Disconnect the battery negative lead.
2Turn the steering wheel as necessary to
expose the two front steering column shroud
securing screws, which are covered by plastic
caps. Prise out the caps and remove the
screws.
3Remove the three securing screws from the
underside of the lower column shroud, then
remove both the upper and lower shrouds.
4To remove the lock cylinder, insert the
ignition key and turn it to position “II”.
5Insert a thin rod into the hole in the lock
housing, then press the rod to release the
detent spring, and pull out the lock cylinder
using the key.
6The ignition switch is secured to the
steering lock housing by two grub screws.
Disconnect the wiring plug, and remove the
screws to extract the switch (see illustration).
Removal of the steering wheel, may aid
removal. Refer to Chapter 10 or Section 57, as
applicable. It is recommended that the switch
and the lock cylinder are not both removed at
the same time, so that their mutual alignment
is not lost.
Refitting
7Refitting is a reversal of removal.
Body electrical systems 12•3
3.11 Relays in engine compartment box -
2.0 litre SRi model shown
4.6 Removing an ignition switch securing
screw
3.5 Removing a fuse -
2.0 litre model shown3.2 Main fuses and relays in facia panel -
2.0 litre SRi model shown
12

2Disconnect the washer hose and withdraw
the nozzle.
Refitting
3To refit, reconnect the washer hose to the
nozzle, and push the nozzle into its locating
hole.
4The nozzles can be adjusted by inserting a
pin into the jet, and swivelling it to the
required position.
1991-on models
5The nozzles on all later models are fitted
with twin jets.
6On some later models, the nozzles are
heated; the circuit is fed through fuse 29 and
is live whenever the ignition is switched on.
Current is regulated by a Positive
Temperature Coefficient (PTC) resistor that
takes outside temperature into account.
38Windscreen wiper motor and
linkage - removal and refitting
3
Removal
1Disconnect the battery negative lead.
2Remove the wiper arms, as described in
Section 36.
3Remove the windscreen cowl panel, as
described in Chapter 11.
4Disconnect the wiring plug from the motor
(see illustration). 5Unscrew the three bolts securing the
motor/linkage assembly to the body, then
withdraw the assembly (see illustrations).
6If desired, the motor can be removed from
the linkage by unscrewing the three securing
bolts. Do not attempt to dismantle the linkage.
Refitting
7Refitting is a reversal of removal.
39Tailgate wiper motor -
removal and refitting
3
Removal
1Disconnect the battery negative lead.
2Remove the wiper arm, as described in
Section 36.
3Extract the securing screws, and remove
the rear tailgate trim panel.
4Disconnect the motor wiring plug.
5Unscrew the two motor securing bolts,
noting the earth leads under the bolt heads
(see illustration).
6Manipulate the motor assembly from the
tailgate.
Refitting
7Refitting is a reversal of removal, ensuring
that the cut-out in the drive spindle rubber
seal engages with the notch in the drive
spindle (see illustration).
40Headlamp wiper motor -
removal and refitting
3
Removal
1Disconnect the battery negative lead.
2Remove the wiper arm, as described in
Section 36.
3Remove the headlamp, as described in
Section 25.
4Disconnect the motor wiring plug.
5Unscrew the two bolts securing the motor
mounting bracket to the body panel, then
withdraw the motor (see illustrations).
Refitting
6Refitting is a reversal of removal.
12•14Body electrical systems
38.4 Disconnecting the windscreen wiper
motor wiring plug
38.5B . . . then withdraw the assembly
40.5B . . . and withdraw the motor40.5A Unscrew the headlamp wiper motor
securing bolts . . .39.7 Cut-out in tailgate wiper motor drive
spindle rubber seal must engage with
notch in drive spindle
39.5 Tailgate wiper motor assembly. Note
earth leads under heads of securing bolts
38.5A Unscrew the windscreen wiper
motor/linkage assembly securing bolts . .