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
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
6If the voltage is 6 volts, the element is okay
(there is no break). If the voltage is 12 volts,
the element is broken between the centre
of the element and the positive end. If the
voltage is 0 volts the element is broken
between the centre of the element and earth.
7To find the break, place the voltmeter
positive lead against the defogger positive
terminal. Place the voltmeter negative lead
with the foil strip against the heating element
at the positive terminal end and slide it toward
the negative terminal end. The point at which
the voltmeter deflects from zero to several
volts is the point at which the heating element
is broken (see illustration).
Repair
8Repair the break in the element using a
repair kit specifically recommended for this
purpose.
9Prior to repairing a break, turn off the system
and allow it to cool off for a few minutes.
10Lightly buff the element area with fine
steel wool, then clean it thoroughly with
rubbing alcohol.
11Use masking tape to mask off the area
being repaired.
12Thoroughly mix the epoxy, following the
instructions provided with the repair kit.
13Apply the epoxy material to the slit in the
masking tape, overlapping the undamaged
area about 3/4-inch on either end (see
illustration).
14Allow the repair to cure for 24 hours before
removing the tape and using the system.
17 Headlights- renewal
1
Warning: Later models are
equipped with halogen gas-filled
headlight bulbs which are underpressure and may shatter if the surface is
damaged or the bulb is dropped. Wear eye
protection and handle the bulbs carefully,
grasping only the base whenever possible.
Do not touch the surface of the bulb with
your fingers because the oil from your skin
could cause it to overheat and fail
prematurely. If you do touch the bulb
surface, clean it with rubbing alcohol.
Sealed beam units
1Remove the radiator grille (see Chapter 11).
2Detach the headlight bezel trim cover (see
illustration).
3Remove the headlight bezel (see
illustrations).
4Remove the screws which secure the
retaining ring and withdraw the ring. Support
the light as this is done (see illustration).
Body electrical system 12•9
12
16.13 Apply masking tape to the inside of
the window at the damaged area, then
brush on the special conductive coating17.2 Remove the screws (arrowed) and
detach the headlight bezel trim cover
17.3a Remove the two retaining screws
at the top and the one in the grille opening
(arrowed)17.3b The retaining screw at the
outside lower corner can be accessed
from under the bumper
3261 Jaguar XJ6 16.5 To determine if a heating element has broken, check the
voltage at the centre of each element. If the voltage is 6-volts, the
element is unbroken; if the voltage is 12-volts, the element is
broken between the centre and the positive end. If there is no
voltage, the element is broken between the centre and earth
16.7 To find the break, place the voltmeter positive lead against
the heated window positive terminal, place the voltmeter negative
lead with the foil strip against the heating element at the positive
terminal end and slide it toward the negative terminal end -
the point at which the voltmeter reading changes abruptly is the
point at which the element is broken
Rear direction indicator,
brake, tail and reversing lights
4Open the boot and remove the plastic
knobs securing the tail light housing trim
cover (see illustration).
5Remove two more plastic knobs and
detach the tail light bulb cluster from the rear
tail light housing. The defective bulb can then
be pulled out of the socket and replaced (see
illustration).
Number plate light
6Remove the lens retaining screws (see
illustration).
7Detach the lens and renew the defective
bulb.
High-mounted brake light
8The brake light cover is retained by screws.
Remove the cover and renew the bulb.
Interior lights
9Remove the overhead console (Chapter 11).
Detach the bulb from the retaining clips and
renew the bulb (see illustration).
Instrument cluster illumination
10To gain access to the instrument cluster
illumination lights, the instrument cluster
housing will have to be removed (Chapter 11).
The bulbs can then be removed and replaced
from the rear of the cluster (see illustration).
22 Inertia switch-
description and check
1
1The inertia switch is a safety mechanism
which governs various electrical circuits such
as the central locking, electric window and
ignition circuits. In the event of a crash, the
inertia switch will automatically unlock the
doors, shut off power to all ignition circuits,
and lock the boot lid and the fuel filler cap.
2To test the inertia switch, turn the ignition
key to the ON position, then lock the driver
and passenger side doors and unlock the
boot lid. Then simply pull upward on the
trip/reset button located on top of the inertiaswitch. All ignition circuits should shut off, the
doors should unlock and the boot lid should
lock. To reset the inertia switch, simply push
downward on the trip/reset button (see
illustration).
12•12 Body electrical system
21.6 Detach the lens retaining screws
(arrowed) and the lens to access the
number plate light bulbs21.9 The interior light bulbs can be
accessed after lowering the overhead
console21.10 To remove an instrument cluster
bulb, depress the bulbholder and rotate it
anti-clockwise
3261 Jaguar XJ6 21.4 The Rear direction indicator, brake, tail and reversing light
bulbs are accessible from the boot compartment after removing
the plastic knobs (arrowed) securing the bulb housing covers
21.5 Remove the bulb cluster from the tail light housing - The
bulb is removed by pushing in and turning the bulb anti-clockwise
22.2 The inertia switch is located behind
the passengers side kick panel - pull
upward on the button to trip the switch -
push downward on the button
to reset the switch
23 Cruise control system-
description and check
5
1The cruise control system maintains vehicle
speed with an independently operated vacuum
motor located on the passenger’s side inner
wing in the engine compartment. When the
cruise control switch is turned on, a vacuum
actuator (connected the throttle linkage) is
activated by vacuum from the vacuum motor.
The system consists of the vacuum motor,
vacuum actuator, brake switch, control
switches, a relay and associated vacuum
hoses. Some features of the system require
special testers and diagnostic procedures
which are beyond the scope of this manual.
Listed below are some general procedures that
may be used to locate common problems.
2Locate and check the fuse (see Section 3).
3Have an assistant operate the brake lights
while you check their operation (voltage from
the brake light switch deactivates the cruise
control).
4If the brake lights don’t come on or don’t
shut off, correct the problem and re-test the
cruise control.
5Visually inspect the vacuum hose
connected to the vacuum motor and vacuum
actuator. Check the freeplay between the
vacuum actuator stop and the throttle link slot
(see illustration).
6Test drive the vehicle to determine if the
cruise control is now working. If it isn’t, take it
to a dealer service department or an
automotive electrical specialist for further
diagnosis and repair.
24 Electric window system-
description and check
2
1The electric window system operates
electric motors, mounted in the doors, which
lower and raise the windows. The system
consists of the control switches, relays, the
motors, regulators, glass mechanisms and
associated wiring.
2The electric windows can be lowered and
raised from the master control switch by the
driver or by remote switches located at the
individual windows. Each window has a
separate motor which is reversible. The
position of the control switch determines the
polarity and therefore the direction of
operation.
3The circuit is protected by a fuse. Each
motor is also equipped with an internal circuit
breaker, this prevents one stuck window from
disabling the whole system.
4The electric window system will only
operate when the ignition switch is ON. In
addition, many models have a window lockout
switch at the master control switch which,
when activated, disables the switches at the
rear windows and, sometimes, the switch at
the passenger’s window also. Always check
these items before diagnosing a window
problem.
5These procedures are general in nature, so
if you can’t find the problem using them, take
the vehicle to a dealer service department or
other properly equipped repair facility.
6If the electric windows won’t operate,
always check the fuse first.
7If only the rear windows are inoperative, or
if the windows only operate from the master
control switch, check the rear window lockout
switch for continuity in the unlocked position.
Renew it if it doesn’t have continuity.
8Check the wiring between the switches andfuse panel for continuity. Repair the wiring, if
necessary.
9If only one window is inoperative from the
master control switch, try the other control
switch at the window. Note:This doesn’t
apply to the driver’s door window.
10If the same window works from one
switch, but not the other, check the switch for
continuity.
11If the switch tests OK, check for a short or
open in the circuit between the affected
switch and the window motor.
12If one window is inoperative from both
switches, remove the trim panel from the
affected door and check for voltage at the
switch and at the motor while the switch is
operated (see illustration).
13If voltage is reaching the motor,
disconnect the glass from the regulator (see
Chapter 11). Move the window up and down
by hand while checking for binding and
damage. Also check for binding and damage
to the regulator. If the regulator is not
damaged and the window moves up and
down smoothly, renew the motor. If there’s
binding or damage, lubricate, repair or renew
parts, as necessary.
14If voltage isn’t reaching the motor, check
the wiring in the circuit for continuity between
the switches and motors. You’ll need to
consult the wiring diagram for the vehicle.
If the circuit is equipped with a relay, check
that the relay is earthed properly and receiving
voltage.
15Test the windows after you are done to
confirm proper repairs.
25 Central locking system-
description and check
5
The central locking system operates the
door lock actuators mounted in each door.
The system consists of the switches, relays,
Body electrical system 12•13
12
3261 Jaguar XJ6 23.5 Check the cruise control throttle linkage for binding
24.12 If no voltage is present at the motor with the switch
depressed, check for voltage at the switch
actuators, a control unit and associated
wiring. Diagnosis can usually be limited to
simple checks of the wiring connections and
actuators for minor faults which can be easily
repaired. Since this system uses an electronic
control unit, in-depth diagnosis should be left
to a dealership service department.
Central locking systems are operated by bi-
directional solenoids located in the doors. The
lock switches have two operating positions;
Lock and Unlock. When activated, the switch
sends a signal to the door lock control unit to
lock or unlock the doors. Depending on which
way the switch is activated, the control unit
reverses polarity to the solenoids, allowing the
two sides of the circuit to be used alternately
as the feed (positive) and earth side.
Some vehicles may have an anti-theft
system incorporated into the locks. If you are
unable to locate the trouble using the following
general paragraphs, consult a dealer service
department or other properly equipped repair
facility.
1Always check the circuit protection first.
Some vehicles use a combination of circuit
breakers and fuses.
2Operate the door lock switches in both
directions (Lock and Unlock) with the engine off.
Listen for the click of the solenoids operating.
3Test the switches for continuity. Renew the
switch if there’s not continuity in both switch
positions.
4Check the wiring between the switches,
control unit and solenoids for continuity.
Repair the wiring if there’s no continuity.
5Check for a bad earth at the switches or the
control unit.
6If all but one lock solenoid operates,
remove the trim panel from the affected door
(see Chapter 11) and check for voltage at the
solenoid while the lock switch is operated
(see illustration). One of the wires should
have voltage in the Lock position; the other
should have voltage in the Unlock position.
7If the inoperative solenoid is receiving
voltage, renew the solenoid.
8If the inoperative solenoid isn’t receiving
voltage, check for an open or short in the wire
between the lock solenoid and the control
unit. Note:It’s common for wires to break in
the portion of the harness between the body
and door (opening and closing the door
fatigues and eventually breaks the wires).26 Electric mirrors-
description and check
2
1Most electric mirrors use two motors to
move the glass; one for up and down
adjustments and one for left-right adjustments.
2The control switch has a selector portion
which sends voltage to the left or right side
mirror. With the ignition ON but the engine
OFF, roll down the windows and operate the
mirror control switch through all functions
(left-right and up-down) for both the left and
right side mirrors.
3Listen carefully for the sound of the electric
motors running in the mirrors.
4If the motors can be heard but the mirror
glass doesn’t move, there’s probably a
problem with the drive mechanism inside the
mirror. Remove and dismantle the mirror to
locate the problem.
5If the mirrors don’t operate and no sound
comes from the mirrors, check the fuse (see
Chapter 1).
6If the fuse is OK, remove the mirror control
switch from its mounting without
disconnecting the wires attached to it. Turn
the ignition ON and check for voltage at the
switch. There should be voltage at one
terminal. If there’s no voltage at the switch,
check for an open or short in the circuit
between the fuse panel and the switch.
7If there’s voltage at the switch, disconnect
it. Check the switch for continuity in all its
operating positions. If the switch does not
have continuity, renew it.
8Re-connect the switch. Locate the wire
going from the switch to earth. Leaving the
switch connected, connect a jumper wire
between this wire and earth. If the mirror
works normally with this wire in place, repair
the faulty earth connection.
9If the mirror still doesn’t work, remove the
mirror and check the wires at the mirror for
voltage. Check with ignition ON and the mirror
selector switch on the appropriate side.
Operate the mirror switch in all its positions.
There should be voltage at one of the switch-
to-mirror wires in each switch position (except
the neutral “off” position).
10If there’s not voltage in each switch
position, check the circuit between the mirror
and control switch for opens and shorts.
11If there’s voltage, remove the mirror and
test it off the vehicle with jumper wires. Renew
the mirror if it fails this test.
27 Electric sunroof-
description and check
2
1The electric sunroof is powered by a single
motor in the roof behind the overhead console.
The power circuit is protected by a fuse.
2The control switches (tilt and slide) send an
earth signal to the sunroof motor when theswitches are pressed. Power is supplied to
the motor from the relay. With the ignition ON
but the engine OFF, operate the sunroof
control switch through the tilt and slide
functions.
3Listen carefully for the sound of the sunroof
motor running in the roof.
4If the motors can be heard but the sunroof
glass doesn’t move, there’s probably a
problem with the drive mechanism or drive
cables.
5If the sunroof does not operate and no
sound comes from the motor, check the fuse
(see Chapter 1).
6If the fuse is OK, remove the control
switches (see Chapter 11). Disconnect the
wires attached to it. Turn the ignition ON and
check for voltage at the switch. If there’s no
voltage at the switch, check for power and
earth at the motor. If power and earth exist at
the motor and there’s still no voltage at the
switch renew the motor. If there’s no voltage
at the motor, check the relay or an open or
short in the wiring between the relay and the
motor.
7If there’s voltage at the switch, disconnect
it. Check the switch for continuity in all its
operating positions. If the switch does not
have continuity, renew it.
8If the switch has continuity re-connect the
switch. Locate the wire going from the switch
to earth. Leaving the switch connected,
connect a jumper wire between this wire and
earth. If the motor works normally with this
wire in place, repair the faulty earth
connection.
9The sunroof can be closed manually by
inserting the T-handle spanner which is
located inside the overhead console. Insert
the spanner into the motor drive shaft and
rotate the shaft clockwise (see illustration).
28 Airbag system-
general information
Warning: Failure to follow these
precautions could result in
accidental deployment of the
airbag and personal injury.
12•14 Body electrical system
25.6 Check for voltage at the lock
solenoid while the lock switch is operated27.9 To close the sunroof manually, insert
the T-handle spanner in the motor shaft
and rotate it clockwise
3261 Jaguar XJ6
Wiring diagrams 12•35
12
3261 Jaguar XJ6
Typical 1988 to 1992 electric windows
12•36 Wiring diagrams
3261 Jaguar XJ6
Typical 1993 and 1994 electric windows