light LAND ROVER DEFENDER 1996 Owner's Guide

86ELECTRICAL
12
DESCRIPTION AND OPERATION VEHICLE ALARM SYSTEM BUILT-IN TEST
NOTE: The handset should be detached
from the key to allow perimetric testing of
the alarm system. The system will
automatically switch to volumetric testing if the
handset is in close proximity to the starter switch.
The built-in test procedure can be accessed providing
the following conditions exist:
Alarm disarmed.
Ignition 'off'.
Doors unlocked.
Bonnet closed.
With assistance, the test mode can be entered by
completing the following instructions within 5 seconds:
1.Open bonnet.
2.Turn starter switch 'on'.
3.Open driver's door (far enough to activate door
switch).
4.Turn starter switch 'off'.
5.Turn starter switch 'on'.
If the test mode has been correctly accessed, the
alarm sounder/horn will operate briefly and the
anti-theft alarm indicator and direction indicator lamps
will flash.
Perimetric tests
The anti-theft alarm indicator light and direction
indicator lamps will flash when:
1.Door switches are activated.
2.The bonnet is opened.
3.Key switches are activated.Volumetric tests
Press the LH (unlock) button or move the handset
close to the starter switch to disable perimetric testing
and enable volumetric testing. If movement is
detected within the vehicle by the ultrasonic sensor
the anti-theft alarm indicator and direction indicator
lamps will illuminate.
NOTE: Exit the anti-theft alarm built-in test
by turning the starter switch to the 'off'
position.
If the previously described conditions are not achieved
during the built-in test procedure, this would indicate a
fault in the alarm system. Before undertaking detailed
fault diagnosis procedures, first make visual checks of
components such as a faulty door switch or blown
alarm system fuse.

ELECTRICAL
1
REPAIR ELECTRICAL PRECAUTIONS
The following guidelines are intended to ensure the
safety of the operator whilst preventing damage to
electrical and electronic components fitted to the
vehicle.
Polarity
Never reverse connect the vehicle battery and always
observe the correct polarity when connecting test
equipment.
High voltage circuits
WARNING: Before commencing work on
an ignition system, all high tension
terminals, adaptors and diagnostic
equipment for testing should be inspected to
ensure that they are adequately insulated and
shielded to prevent accidental personal contacts
and minimize the risk of shock. Wearers of
surgically implanted pacemaker devices should
not be in close proximity to ignition circuits or
diagnostic equipment.
Whenever disconnecting live high tension circuits
always use insulated pliers and never allow the open
end of a high tension lead to come into contact with
other components particularly electronic control units.
Exercise caution when measuring the voltage on the
coil terminals while the engine is running, since, high
voltage spikes can occur on these terminals.
Connectors and harness
Always ensure that these items are dry and oil free
before disconnecting and connecting test equipment.
Never force connectors apart either by using tools or
by pulling on the wiring harness. Always ensure
locking tabs are disengaged before removal and note
orientation to enable correct reconnection. Ensure that
any protective covers and substances are replaced if
disturbed. Having confirmed a component to be faulty
switch-off the ignition and disconnect the battery.
Remove the component and support the disconnected
harness. When replacing the component keep oily
hands away from electrical connection areas and
push connectors home until any locking tabs fully
engage.Battery disconnecting
Before disconnecting the battery, switch off all
electrical equipment.
Battery charging
Recharge the battery out of the vehicle and keep the
top well ventilated. While being charged or
discharged, and for approximately 15 minutes
afterwards, batteries emit hydrogen gas which is
flammable. Always ensure any battery charging area
is well ventilated and that every precaution is taken to
avoid naked flames and sparks.
GENERAL PRECAUTIONS
Switch-off ignition prior to making any connection or
disconnection in the system as electrical surge
caused by disconnecting 'live' connections can
damage electronic components.
Ensure hands and work surfaces are clean and free of
grease, swarf, etc. as grease collects dirt which can
cause tracking or high-resistance contacts.
When handling printed circuit boards, treat them as
you would a disc - hold by the edges only.
Prior to commencing a test, and periodically during a
test, touch a good earth, for instance, a cigar lighter
socket, to discharge body static as some electronic
components are vulnerable to static electricity.

ELECTRICAL
3
REPAIR ELECTRONIC CONTROL UNIT (ECU)
Service repair no - 86.55.85
Remove
1.Remove LH front seat cushion.
2.Release retaining clip and remove battery
access cover.
3.Slacken battery negative lead clamp bolt.
4.Turn starter switch 'on'.
5.Turn starter switch 'off' and remove key.
6.Disconnect battery negative lead.
NOTE: Operation 6 needs to be carried out
within 15 seconds to avoid activating
battery backed-up alarm sounder, if fitted.
7.Remove steering wheel
See STEERING,
Repair, Steering wheel.
8.Remove 4 screws securing instrument panel to
fascia cowl
See INSTRUMENTS, Repair,
Instrument panel.
9.Pull instrument panel away from fascia cowl and
disconnect speedometer cable, multi-plugs,
alarm LED plug lead, heated rear screen lead,
gearbox oil temperature lead and immobiliser
warning light leads.
10.Remove instrument panel.
11.Remove 2 screws securing ECU to fascia cowl
(LH drive shown). On RH drive vehicles ECU is
positioned lower down, on vertical face of fascia
panel.
12.Release ECU from fascia cowl and disconnect
both multi-plugs.
13.Remove ECU.
NOTE: A new ECU must be initialised
using TestBook.
Refit
14.Position ECU at fascia cowl and reconnect both
multi-plugs.
15.Locate ECU on mounting face of fascia cowl and
secure with 2 screws.
16.Position instrument panel to fascia cowl and
reconnect immobiliser warning light leads,
gearbox oil temperature lead, heated rear screen
lead, alarm LED plug lead, multi-plugs and
speedometer cable.
17.Secure instrument panel to fascia cowl with 4
screws
See INSTRUMENTS, Repair,
Instrument panel.
18.Fit steering wheelSee STEERING, Repair,
Steering wheel.
19.Reconnect battery negative lead.
20.Fit battery access cover.
21.Fit LH seat cushion.

86ELECTRICAL
4
REPAIR HANDSET BATTERY
Service repair no - 86.77.13
Remove
1.Unlock vehicle and disarm alarm system.
2.Turn starter switch to position 'II'.
3.Turn starter switch back to position '0' and
remove key.
4.Carefully prise handset apart, starting from
keyring end, using a coin or small screwdriver.
5.Slide battery out from retaining clip.
6.Press and hold one of the handset buttons for at
least five seconds to drain any residual power
from handset.
NOTE: The engine will immobilise five
minutes after key is removed from starter
switch.Refit
7.Fit new battery into handset retaining clip with
positive side uppermost. Finger marks will
adversely affect battery life; if possible, avoid
touching flat surfaces of battery and wipe clean
before fitting.
8.Reassemble two halves of handset.
9.Press RH (Padlock) button at least four times
within range of vehicle to resynchronise handset.
10.Check operation of alarm system.
WARNING: The handset contains delicate
electronic circuits and must be protected
from impact and water damage, high
temperatures and humidity, direct sunlight and
effects of solvents, waxes and abrasive cleaners.
NOTE: New handsets must be be
initialised using TestBook.

ELECTRICAL
5
REPAIR PASSIVE COIL
Service repair no - 86.77.35
Remove
1.Remove LH front seat cushion.
2.Release retaining clip and remove battery
access cover.
3.Slacken battery negative lead clamp bolt.
4.Turn starter switch 'on'.
5.Turn starter switch 'off' and remove key.
6.Disconnect battery negative lead.
NOTE: Operation 6 needs to be carried out
within 15 seconds to avoid activating
battery backed-up alarm sounder, if fitted.
7.Remove steering wheel
See STEERING,
Repair, Steering wheel.
8.Remove 4 screws securing instrument panel to
fascia cowl
See INSTRUMENTS, Repair,
Instrument panel.
9.Pull instrument panel away from fascia and
disconnect speedometer cable, multi-plugs,
alarm LED plug lead, heated rear screen lead,
gearbox oil temperature lead and immobiliser
warning light leads.
10.Remove instrument panel.
11.Remove 7 screws securing upper and lower
halves of nacelle to steering column mounting
bracket
See STEERING, Repair, Steering
column nacelle.
12.Release multi-switch gaiters from both sides of
nacelle.
13.Remove nacelle upper and lower halves from
steering column; collect blanking grommet from
RH side.
14.Disconnect multi-plug and remove passive coil
from starter switch.
Refit
15.Feed passive coil plug lead into fascia cowl area
and reconnect multi-plug .
16.Fit coil on starter switch.
17.Position nacelle upper and lower halves to
steering column mounting bracket and secure
with 7 screws. Do not fully tighten screws at this
stage
See STEERING, Repair, Steering
column nacelle.
18.Check that passive coil is still fitted correctly on
starter switch.
19.Check fit of nacelle at starter switch and steering
column and fully tighten fixing screws.
20.Fit multi-switch gaiters to both sides of nacelle
and check that blanking grommet is located.
21.Position instrument panel to fascia cowl area
and reconnect immobiliser warning light leads,
gearbox oil temperature lead, heated rear screen
lead, alarm LED plug lead, main harness multi-
plugs and speedometer.
22.Secure instrument panel to fascia cowl with 4
screws
See INSTRUMENTS, Repair,
Instrument panel.
23.Fit steering wheelSee STEERING, Repair,
Steering wheel.
24.Reconnect battery negative lead.
25.Fit battery access cover.
26.Fit LH seat cushion.
27.Test immobilisation and alarm system.

ELECTRICAL
9
REPAIR ALARM SOUNDER RELAY
Service repair no - 86.77.09
Remove
1.Remove screw and lift off LH door check strap
cover.
2.Remove 3 screws and lower wiper motor cover
from fascia bulkhead, (on RH drive models first
remove grab handle).
3.Slide relay multi-plug from retaining bracket and
remove relay.
Refit
4.Secure multi-plug to mounting bracket and fit
new relay.
5.Position wiper motor cover and secure with 3
screws.
6.On RH drive models fit grab handle.
7.Fit door check strap and secure with screw.ANTI-THEFT ALARM INDICATOR LIGHT
Service repair no - 86.45.61
Remove
1.Remove LH front seat cushion.
2.Release retaing clip and remove battery access
cover.
3.Slacken battery negative lead clamp bolt.
4.Turn starter switch 'on'.
5.Turn starter switch 'off' and remove key.
6.Disconnect battery negative lead.
NOTE: Operation 6 needs to be carried out
within 15 seconds to avoid activating
battery backed-up alarm sounder, if fitted.
NOTE: If an alarm sounder without battery
back-up is fitted, it is not necessary to
disconnect battery.
7.Remove steering wheel
See STEERING,
Repair, Steering wheel.
8.Remove 4 screws securing instrument panel to
fascia cowl.
9.Pull instrument panel away from fascia and
disconnect speedometer cable, if necessary.
10.Disconnect alarm indicator light plug lead.
11.Press in retaining lugs and withdraw indicator
light from fascia panel.

86ELECTRICAL
10
REPAIR Refit
12.Fit alarm indicator light into fascia panel and
reconnect plug lead.
13.Reconnect speedometer cable and fit instrument
panel to fascia cowl.
14.Fit steering wheel
See STEERING, Repair,
Steering wheel.
15.Reconnect battery negative lead.
16.Fit battery access cover.
17.Fit LH seat cushion.ALARM SYSTEM FUSE
Service repair no - 86.77.04
Remove
1.Remove LH front seat cushion.
2.Release retaining clip and remove battery
access cover.
3.Slacken battery negative lead clamp bolt.
4.Turn starter switch 'on'.
5.Turn starter switch 'off' and remove key.
6.Disconnect battery negative lead.
NOTE: Operation 6 needs to be carried out
within 15 seconds to avoid activating
battery backed-up alarm sounder, if fitted.
NOTE: If an alarm sounder without battery
back-up is fitted, it is not necessary to
disconnect battery.
7.Remove steering wheel
See STEERING,
Repair, Steering wheel.
8.Remove 4 screws securing instrument panel to
fascia cowl
See INSTRUMENTS, Repair,
Instrument panel.
9.Pull instrument panel away from fascia and
disconnect speedometer cable, main harness
multi-plugs, alarm LED plug lead, heated rear
screen leads, gearbox oil temperature lead and
immobiliser warning light lead.
10.Remove instrument panel.
11.Remove alarm system 15 amp (blue) fuse from
holder located behind starter switch.

ELECTRICAL
11
REPAIR REV: 05/99 Refit
12.Fit new fuse.
13.Position instrument panel to fascia cowl area
and reconnect immobiliser warning light leads,
gearbox oil temperature lead, heated rear screen
leads, alarm LED plug lead, main harness
multi-plugs and speedometer cable,
14.Secure instrument panel to fascia cowl with 4
screws
See INSTRUMENTS, Repair,
Instrument panel.
15.Fit steering wheelSee STEERING, Repair,
Steering wheel.
16.Reconnect battery negative lead.
17.Fit battery access cover.
18.Fit LH front seat cushion.GENERATOR
Service repair no - 86.10.02
Remove
1.Disconnect battery.
2.Remove drive belt
See Auxiliary drive belt.
3.Unscrew 3 fixings, remove heat shield from rear
of generator, and disconnect electrical leads
from generator.
4.Remove generator bottom fixing bolt.
5.Remove long through bolt from top fixing and lift
generator from engine.
Refit
6.Fit generator to engine mounting bracket and
secure with top and bottom fixing bolts.
7.Connect electrical leads.
8.Fit heat shield.
9.Fit drive belt
See Auxiliary drive belt; Refit.
10.Reconnect battery.

86ELECTRICAL
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REPAIR REVERSE LAMP SWITCH
Service repair no - 37.27.01
Remove
The reverse lamp switch is located on the LH side of
the gearbox extension housing and is accessible from
underneath the vehicle.
1.Place vehicle on suitable ramp.
2.Disconnect reverse lamp switch lead multi-plug
from harness connector.
3.Unscrew switch from extension housing.
Refit
4.Fit new switch to gearbox extension housing.
Tighten to
25 Nm (18 lbf/ft).
5.Fit lamp switch lead multi-plug to harness
connector.
6.Check operation of lamp switch.WARNING LAMP ASSEMBLY
Service repair no - 86.45.60 - Warning lamp
assembly
Service repair no - 86.45.61 - Warning lamp bulb
renewal
Remove
1.Disconnect battery.
2.Remove 2 screws and withdraw warning light
assembly from instrument panel.
3.Remove multi-plug to give access to warning
lamp bulbs.
4.Twist bulb holder and pull it from its socket.
5.Pull bulb from holder.
Refit
6.Fit new bulb and refit holder.
7.Fit multi-plug.
8.Fit warning lamp assembly to instrument panel
9.Reconnect battery.

86ELECTRICAL
20
REPAIR WINDSCREEN WIPER/WASHER SWITCH
Service repair no - 84.15.34
Remove
1.Remove steering column nacelle
See
STEERING, Repair, Steering column nacelle.
2.Disconnect switch multi-plug from main harness.
3.Remove 2 screws and star washer securing
switch to mounting bracket.
4.Remove switch complete with harness.
Refit
5.Fit new switch to mounting bracket.
6.Reconnect switch multi-plug.
7.Fit steering column nacelle
See STEERING,
Repair, Steering column nacelle.
DIRECTION INDICATOR/HEADLAMP/HORN
SWITCH
Service repair no - 86.65.55
Remove
1.Remove steering column nacelle
See
STEERING, Repair, Steering column nacelle.
2.Disconnect 3 steering column switch multi-plugs
from main harness.
3.Slacken clamp screw and withdraw switch
assembly from steering column.
4.Remove fixings and detach windscreen
wiper/washer and main lighting switches from
mounting bracket.
5.Renew complete direction
indicator/headlamp/horn switch and switch
bracket assembly.
Refit
6.Fit main lighting and windscreen wiper/washer
switches to mounting bracket.
7.Position switch assembly on steering column
and fully tighten clamp.
8.Reconnect switch multi-plugs.
9.Fit steering column nacelle
See STEERING,
Repair, Steering column nacelle.