3261 Jaguar XJ6
12
Chapter 12
Body electrical system
1 General information
The electrical system is a 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 the engine.
Information on the battery, alternator,
distributor and starter motor will be found in
Chapter 5.
It should be noted that when portions of the
electrical system are serviced, the cable
should be disconnected from the negative
battery terminal to prevent electrical shorts
and/or fires.
2 Electrical fault finding-
general information
A typical electrical circuit consists of an
electrical component, any switches, relays,
motors, fuses, fusible links, in-line fuses or
circuit breakers related to that component
and the wiring and electrical connectors that
link the component to both the battery andthe chassis. To help you pinpoint an electrical
circuit problem, wiring diagrams are included
at the end of this Chapter.
Before tackling any troublesome electrical
circuit, first study the appropriate wiring
diagrams to get a complete understanding of
what makes up that individual circuit. Trouble
spots, for instance, can often be narrowed
down by noting if other components related to
the circuit are operating properly. If several
components or circuits fail at one time,
chances are the problem is in a fuse or earth
connection, because several circuits are often
routed through the same fuse and earth
connections.
Electrical problems usually stem from
simple causes, such as loose or corroded
connections, a blown fuse, a melted fusible
link or a bad relay. Visually inspect the
condition of all fuses, wires and connections
in a problem circuit before diagnosing it.
If testing instruments are going to be
utilised, use the diagrams to plan ahead of
time where you will make the necessary
connections in order to accurately pinpoint
the trouble spot.
The basic tools needed for electrical fault
finding include a circuit tester or voltmeter (a
12-volt bulb with a set of test leads can also
be used), a continuity tester, which includes a
bulb, battery and set of test leads, and a
jumper wire, preferably with a circuit breaker
incorporated, which can be used to bypasselectrical components. Before attempting to
locate a problem with test instruments,
use the wiring diagram(s) to decide where to
make the connections.
Voltage checks
Voltage checks should be performed if a
circuit is not functioning properly. Connect
one lead of a circuit tester to either the
negative battery terminal or a known good
earth. Connect the other lead to a electrical
connector in the circuit being tested,
preferably nearest to the battery or fuse. If the
bulb of the tester lights, voltage is present,
which means that the part of the circuit
between the electrical connector and the
battery is problem free. Continue checking the
rest of the circuit in the same fashion. When
you reach a point at which no voltage is
present, the problem lies between that point
and the last test point with voltage. Most of
the time the problem can be traced to a loose
connection. Note:Keep in mind that some
circuits receive voltage only when the ignition
key is in the Accessory or Run position.
Finding a short
One method of finding shorts in a circuit is
to remove the fuse and connect a test light or
voltmeter in its place. There should be no
voltage present in the circuit. Move the wiring
harness from side to side while watching the
test light. If the bulb goes on, there is a short Airbag system - general information . . . . . . . . . . . . . . . . . . . . . . . . . 28
Bulb renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Central locking system - description and check . . . . . . . . . . . . . . . . 25
Circuit breakers - general information . . . . . . . . . . . . . . . . . . . . . . . . 5
Cruise control system - description and check . . . . . . . . . . . . . . . . . 23
Direction indicators/hazard flashers - general information . . . . . . . . 7
Electric aerial - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . 14
Electric side view mirrors - description and check . . . . . . . . . . . . . . 26
Electric sunroof - description and check . . . . . . . . . . . . . . . . . . . . . . 27
Electric window system - description and check . . . . . . . . . . . . . . . 24
Electrical fault finding - general information . . . . . . . . . . . . . . . . . . . 2
Fuel, oil and temperature gauges - check . . . . . . . . . . . . . . . . . . . . . 11
Fuses - general information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Headlight housing (1992 to 1994 models) - removal and refitting . . . 19Headlights - adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Headlights - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Heated rear window - check and repair . . . . . . . . . . . . . . . . . . . . . . 16
Horn - check and renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Ignition switch and key lock cylinder - removal and refitting . . . . . . 9
Inertia switch - description and check . . . . . . . . . . . . . . . . . . . . . . . . 22
In-line fuses - general information . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Instrument cluster - removal and refitting . . . . . . . . . . . . . . . . . . . . . 12
Instrument panel switches - removal and refitting . . . . . . . . . . . . . . 10
Radio and speakers - removal and refitting . . . . . . . . . . . . . . . . . . . 13
Relays - general information and testing . . . . . . . . . . . . . . . . . . . . . . 6
Steering column switches - removal and refitting . . . . . . . . . . . . . . . 8
Windscreen wiper motor - removal and refitting . . . . . . . . . . . . . . . . 15
Wiring diagrams - general information . . . . . . . . . . . . . . . . . . . . . . . 29
12•1
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
wash system, radio memory and the ABS
main feed and pump circuits.
In-line fuses are located through out the
vehicle depending on the year, make and
model. Consult the wiring diagrams at the end
of this Chapter for further information.
In-line fuses also have a blade terminal
design, which allow fingertip removal and
renewal. If an electrical component fails,
always check the fuse first. A blown fuse is
easily identified through the clear plastic
body. Inspect the element for evidence of
damage (see illustration 3.3).
Be sure to renew blown fuses with the
correct type. Fuses are usually colour-coded
to indicate their rating. Fuses of different
ratings are physically interchangeable, but
only fuses of the proper rating should be
used. Replacing a fuse with one of a different
value than specified is not recommended.
Each electrical circuit needs a specific
amount of protection. The amperage value of
each fuse is moulded into the fuse body.If the renewal fuse immediately fails, don’t
renew it again until the cause of the problem
is isolated and corrected. Don’t substitute
anything else for the fuse. In most cases, this
will be a short circuit in the wiring caused by a
broken or deteriorated wire.
5 Circuit breakers-
general information
Circuit breakers generally protect
components such as electric windows, central
locking and headlights. On some models the
circuit breaker resets itself automatically, so
an electrical overload in the circuit will cause it
to fail momentarily, then come back on. If the
circuit doesn’t come back on, check it
immediately. Once the condition is corrected,
the circuit breaker will resume its normal
function. Some circuit breakers have a button
on top and must be reset manually.To test a circuit breaker, use an ohmmeter
to check continuity between the terminals. A
reading of zero to 1.0 ohms indicates a good
circuit breaker. An open circuit reading on the
meter indicates a bad circuit breaker.
6 Relays- general information
and testing
2
General information
Several electrical accessories in the vehicle,
such as the fuel injection system, electric
windows, central locking, etc, use relays to
transmit the electrical signal to the component.
Relays use a low-current circuit (the control
circuit) to open and close a high-current circuit
(the power circuit). If the relay is defective, that
component will not operate properly. The
relays are mounted throughout the vehicle (see
illustrations). If a faulty relay is suspected, it
Body electrical system 12•3
12
3261 Jaguar XJ6 1988 to 1989 relay location details
11 Fuel, oil and temperature
gauges- check
1
Warning: Later models are
equipped with airbags. To
prevent accidental deployment
of the airbag, which could cause
personal injury or damage to the airbag
system, DO NOT work in the vicinity of the
steering column or instrument panel. The
manufacturer recommends that, on airbag
equipped models, the following procedure
be performed at a dealer service
department or other properly equipped
repair facility because of the special tools
and techniques required to disable the
airbag system.
1All tests below require the ignition switch to
be turned to ON position when testing.
2Check the fuse if the gauge pointer does
not move from the empty, low or cold
positions. If the fuse is OK, locate the
particular sender unit for the circuit you’re
working on (see Chapter 4 for fuel sender unit
location, Chapter 2 for oil sender unit location,
or Chapter 3 for temperature sender unit
location). Connect the sender unit connector
to earth If the pointer goes to the full, high or
hot position renew the sender unit. If the
pointer stays in same position use a jumper
wire to earth the terminal on the back of the
gauge. If the pointer moves with the back of
the gauge earthed the problem lies in the wire
between the gauge and the sender unit. If the
pointer does not moves with the back of the
gauge earthed check for voltage at the other
terminal of the gauge. If voltage is present
renew the gauge.
12 Instrument cluster-
removal and refitting
1
Warning: Later models are
equipped with airbags. To
prevent accidental deployment
of the airbag, which could cause
personal injury or damage to the airbag
system, DO NOT work in the vicinity of the
steering column or instrument panel. The
manufacturer recommends that, on airbag
equipped models, the following procedure
be performed at a dealer service
department or other properly equipped
repair facility because of the special tools
and techniques required to disable the
airbag system.
Caution: If the stereo in your vehicle is
equipped with an anti-theft system, make
sure you have the correct activation code
before disconnecting the battery.
1Disconnect the negative battery cable.
2Remove the instrument cluster housing (see
Chapter 11).
3Remove the instrument cluster mounting
screws (see illustration). Separate the
instrument cluster from the cluster housing.
4Refitting is the reverse of removal.
13 Radio and speakers-
removal and refitting
2
Warning: Later models are
equipped with airbags. To
prevent accidental deployment
of the airbag, which could cause
personal injury or damage to the airbag
system, DO NOT work in the vicinity of the
steering column or instrument panel. The
manufacturer recommends that, on airbagequipped models, the following procedure
be performed at a dealer service
department or other properly equipped
repair facility because of the special tools
and techniques required to disable the
airbag system.
Caution: If the stereo in your vehicle is
equipped with an anti-theft system, make
sure you have the correct activation code
before disconnecting the battery.
1Disconnect the negative battery cable.
Radio
2Remove the radio trim bezel (Chapter 11).
3Remove the retaining screws (see
illustration), pull the radio/control panel
outward to access the backside and
disconnect the electrical connectors and
aerial lead. Detach the retaining clips and
separate the radio from the control panel.
4Refitting is the reverse of removal.
Speakers
5Remove the door trim panel (Chapter 11).
6Remove the nuts from the speaker
mounting studs (see illustration). Disconnect
the electrical connector and remove the
speaker from the vehicle.
7Refitting is the reverse of removal.
Body electrical system 12•7
12
3261 Jaguar XJ6 12.3 Remove the instrument cluster retaining screws (arrowed)
then separate the instrument cluster from the cluster housing
13.3 Remove the retaining screws (arrowed) and pull the
radio/control panel out enough to unplug the connectors
13.6 Remove the nuts from the retaining
studs (arrowed) to remove the speaker
14 Electric aerial-
removal and refitting
2
Aerial motor assembly
1Remove the aerial mast retaining nut (see
illustration).
2Working in the boot, pry out the plastic
clips securing the driver’s side boot finishing
panels to allow access to the aerial motor
assembly.
3Detach the motor assembly retaining bolts
(see illustration). Disconnect the electrical
connector and earth strap then remove the
aerial motor assembly from the vehicle.
4Refitting is the reverse of removal.
Aerial mast
5Remove the aerial mast retaining nut (see
illustration 14.1).
6With an assistant controlling the ignition
switch, turn the ignition key and the radio to
the ON position. Guide the aerial mast out of
the body as the cable unwinds from the motor
assembly (see illustration). Note the direction
the “teeth” on the aerial cable are facing for
refitting purposes.
7To refit the aerial mast, insert the aerial
cable into the motor assembly with the cable
teeth facing the direction as noted above.
Have your assistant turn the ignition key and
the radio to the ON position. Guide the cableand aerial mast through the opening as the
cable winds back into the motor assembly.
8Refit the aerial mast retaining nut.
15 Windscreen wiper motor-
removal and refitting
2
1Pull the wiper arm nut cover back to access
the wiper arm nuts. Remove the nuts and pull
the wiper arm straight off the shaft (see
illustration).
2Remove the screws and detach the cowl
cover (see Chapter 11).
3Remove the drive spindle nut (see
illustration).
4Remove the retaining bolts located along
the top edge of the wiper motor housing and
detach three retaining clips along the bottom
edge of the wiper motor housing (see
illustration).
5Disconnect the electrical connector and
remove the motor assembly from the vehicle.
6Refitting is the reverse of removal.
16 Heated rear window-
check and repair
2
1The heated rear window consists of a
number of horizontal elements baked onto the
glass surface.2Small breaks in the element can be repaired
without removing the rear window.
Check
3Turn the ignition switch and heated rear
window switches to the ON position.
4When measuring voltage during the next
two tests, wrap a piece of aluminium foil
around the tip of the voltmeter negative probe
and press the foil against the heating element
with your finger (see illustration). Place the
voltmeter positive lead against the heated
window positive terminal.
5Check the voltage at the centre of each
heating element (see illustration).
12•8 Body electrical system
14.1 The aerial mast retaining nut can be
removed with an open end spanner14.3 Remove the retaining bolts (arrowed),
pull the aerial assembly out and unplug the
electrical connectors and aerial lead14.6 With the ignition key and the radio in
the ON position, guide the aerial mast out
of the motor assembly - note the direction
of the “teeth” on the aerial cable
15.1 Lift up the wiper arm nut cover,
remove the nut and pull the wiper arm
straight off the shaft15.3 Use a spanner or socket to remove
the drive spindle retaining nut15.4 Remove the bolts (A) along the
top edge of the housing and detach the
clips (B) along the bottom edge
3261 Jaguar XJ6
16.4 When measuring the voltage at the
heated rear window grid, wrap a piece of
aluminium foil around the negative probe
of the voltmeter and press the foil against
the element with your finger
3261 Jaguar XJ6
Dimensions and weights . . . . . . . . . . . . . . . . . . .REF•1
Jacking and vehicle support . . . . . . . . . . . . . . . .REF•1
Radio/cassette unit anti-theft system . . . . . . . . .REF•1
Conversion factors . . . . . . . . . . . . . . . . . . . . . . .REF•2
Use of English . . . . . . . . . . . . . . . . . . . . . . . . . . .REF•3
Buying spare parts . . . . . . . . . . . . . . . . . . . . . . . .REF•4
Vehicle identification . . . . . . . . . . . . . . . . . . . . . .REF•4General repair procedures . . . . . . . . . . . . . . . . .REF•5
Tools and working facilities . . . . . . . . . . . . . . . . .REF•6
MOT test checks . . . . . . . . . . . . . . . . . . . . . . . . .REF•8
Fault finding . . . . . . . . . . . . . . . . . . . . . . . . . . . .REF•12
Glossary of technical terms . . . . . . . . . . . . . . . .REF•18
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .REF•22
Dimensions and weights
Note:All figures are approximate, and may vary according to model. Refer to manufacturer’s data for exact figures.
Dimensions
Overall length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4988 mm
Overall width (including mirrors) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2015 mm
Overall height (unladen) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1358 mm
Wheelbase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2870 mm
Weights
Kerb weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1770 kg
Maximum gross vehicle weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2190 kg
Maximum towing weight:
Braked trailer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1500 kg
Unbraked trailer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 750 kg
Maximum axle load:
Front axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1050 kg
Rear axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1170 kg
Maximum roof rack load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 kg
ReferenceREF•1
Radio/cassette unit anti-theft system - precaution
Some models are equipped with an audio
system which includes an anti-theft feature, to
deter thieves. If the power source to the unit is
cut, the anti-theft system will activate. Even if
the power source is immediately reconnected,
the radio/cassette unit will not function untilthe correct security code has been entered.
Therefore if you do not know the correct
security code for the unit, do notdisconnect
the battery negative lead, or remove the
radio/cassette unit from the vehicle.The procedure for reprogramming a unit
that has been disconnected from its power
supply varies from model to model - consult
the handbook supplied with the unit for
specific details or refer to your Jaguar dealer. The jack supplied with the vehicle tool kit
should only be used for changing the
roadwheels - see “Wheel changing”at the
front of this manual. When carrying out any
other kind of work, raise the vehicle using a
hydraulic (or “trolley”) jack, and always
supplement the jack with axle stands
positioned under the vehicle jacking points.
To raise the front of the vehicle, place a
block of wood on the jack head and positionthe jack underneath the centre of the front
crossmember. Lift the vehicle to the required
height and support it on axle stands
positioned underneath the vehicle jacking
points on the sills.
To raise the rear of the vehicle, place a
block of wood on the jack head and position
the jack underneath the centre of the rear
crossmember. Lift the vehicle to the required
height and support it on axle standspositioned underneath the vehicle jacking
points on the sills.
The jack supplied with the vehicle locates in
the jacking points on the sills. Ensure that the
jack head is correctly engaged before
attempting to raise the vehicle.
Neverwork under, around, or near a raised
vehicle, unless it is adequately supported in at
least two places.
Jacking and vehicle support
3261 Jaguar XJ6
NNeutral start switch -7•5
Notes for UK readers -0•4, REF•3
Number plate light - 12•12
OObtaining diagnostic code output -6•3
Oil cooler -3•6
Oil filter -1•6
Oil gauge - 12•7
Oil pump -2A•15
Oil seals -2A•5, 2A•17, 2B•17, 7•7, 8•4, 8•5, REF•5
Oil,differential -1•2, 1•11, 1•20
Oil,engine -0•11, 0•16, 1•2, 1•6
On Board Diagnosis (OBD) system -6•2
Open circuit check - 12•2
Output shaft -7•7
Oxygen sensor -6•4
PPads (brake) -9•1, 9•2
Painting - 11•2
Parking lights - 12•11
Piston rings -2B•15
Pistons -2B•9, 2B•12, 2B•17
Poisonous or irritant substances -0•5
Power hydraulic system -0•16
fluid - 1•9
Power steering - 10•10, 10•11
fluid - 0•13, 0•16
Propshaft -1•18, 8•1, 8•2, 8•3
Punctures- 0•8
RRadiator -3•4
grille - 11•5
Radio - 12•7, REF•1
Rear lights - 12•12
Receiver/drier -3•12
Regulator (window) - 11•10
Relays - 12•3
Repair procedures - REF•5
Reversing lights -7•5, 12•12
Road test -1•14
Roadside repairs-0•6et seq
Routine maintenance and servicing-1•1et seq
Rust holes - 11•2
SSafety first -0•5
Scalding -0•5
Scratches - 11•2Screw threads and fastenings - REF•5
Seat belts -1•13, REF•9
Seats - 11•14, REF•9
Self-levelling rear suspension system - 10•3
Servo -1•12, 9•1, 9•9
Shift cable -7•4
Shock absorber - 10•4, 10•6, REF•9, REF•10
Shoes (brake) -1•20, 9•11
Short circuit check - 12•1
Side marker lights - 12•11
Spare parts - REF•4
Spark plugs -1•7, 1•14
Speakers - 12•7
Speed sensor -6•7
Spoiler - 11•5
Springs - 10•5, 10•6, REF•10
Starter motor -5•7
Steering - See Suspension and steering systems
Steering wheel and column - 11•13, 12•5, REF•8
Sump -2A•14
Sunroof - 12•14
Supplementary air valve -4•13
Suspension and steering systems- 1•12, 10•1et seq, REF•9, REF•10
fault finding - REF•16, REF•17
Switches -4•1, 7•5, 9•13, 12•5, 12•6, 12•12
TTail lights - 12•12
Temperature gauge - 12•7
Temperature sender unit -3•7
Thermostat -3•2
Throttle body -4•10
Throttle potentiometer -6•5
Tie-rod ends - 10•9
Timing chains -2A•6
Tools - REF•5, REF•6, REF•7
Top Dead Centre (TDC) for number one piston -2A•2
Torque converter -7•7
Towing -0•6
Trim panels - 11•7, 11•13
Tyres - 0•14, 10•11, REF•11
UUK readers information -0•4, REF•3
Universal joint -8•1, 8•2, 8•5
Upholstery - 11•1
VVacuum gauge checks -2B•3
Valve cover -2A•3
Valve lifters -2A•9
Valves -2B•8
Vehicle identification - REF•4, REF•9
Vehicle support - REF•1
Vinyl trim - 11•1
Voltage checks - 12•1
REF•24Index