fuse box LAND ROVER DEFENDER 1999 Owner's Manual
[x] Cancel search | Manufacturer: LAND ROVER, Model Year: 1999, Model line: DEFENDER, Model: LAND ROVER DEFENDER 1999Pages: 667, PDF Size: 8.76 MB
Page 630 of 667

ELECTRICAL
21
DESCRIPTION AND OPERATION The Heated Front Screen (HFS) is a new feature for 2002MY which is available as part of a cold climate pack on
Td5 engine variants only. The HFS system comprises an HFS ECU, an HFS relay, a controlling switch and the
HFS elements.
The HFS comprises two elements laminated in the windscreen. The elements are connected by bus bars within
the screen and therefore the HFS has only one feed and one earth connector.
The HFS is controlled by the HFS ECU which determines when HFS operation is permitted. The ECU also has a
timer which allows HFS operation for up to 8 minutes. The HFS ECU is located behind the instrument pack,
adjacent to the dim/dip relay. The ECU is connected by a multiplug. The ECU receives an ignition feed via the
satellite fuse box and an engine running signal from the engine oil pressure switch.
A non-latching switch for HFS operation is located in the fascia. The switch has a tell-tale lamp to indicate when
the HFS screen is operative.
The HFS relay is located in the under seat fuse box and receives a permanent battery voltage supply via fusible
link 1 in the under seat fuse box. The relay coil is connected to the HFS ECU and an earth point. When the relay is
operated, battery voltage is supplied from the relay, via fuse 25 in the passenger compartment fuse box to the
HFS element.
When the HFS switch is depressed, a momentary earth path is completed from the HFS ECU, through the switch
to earth. This is sensed by the ECU as a request for HFS operation. If the ECU receives an ignition on signal and
an oil pressure signal, it allows HFS operation. The ECU provides an output to the coil of the HFS relay. When the
coil is energised, the contacts close and battery voltage, via fusible link 1 in the under seat fuse box is supplied to
the HFS element, via fuse 25 in the passenger compartment fuse box. The feed is also supplied via a splice joint
to the HFS switch to illuminate the tell tale lamp in the switch.
The HFS ECU will allow screen operation for up to 8 minutes, after which it removes the feed to the HFS relay
coil, which, after the contacts open, removes the supply to the HFS element and simultaneously extinguishing the
tell tale lamp in the switch. If, during the timed operation period, the HFS ECU receives an additional request
signal from operation of the switch, HFS operation is stopped.
When operating, the HFS element draws approximately 25 Amps. To prevent excess drain on the vehicle battery,
if the ignition on signal and/or the oil pressure switch (engine running) signal is lost, the HFS ECU de-energises, if
already operating, or will not energise the HFS relay.
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Page 631 of 667

86ELECTRICAL
22
DESCRIPTION AND OPERATION HEATED FRONT SEATS - FROM 02MY
1.LH and RH seat heater switches
2.Seat heater cushion and squab elements
3.Seat heat/Window lift relay (passenger compartment fuse box)
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Page 632 of 667

ELECTRICAL
23
DESCRIPTION AND OPERATION Heated front seats are a new feature for 2002MY and are available as part of a cold climate pack on Td5 engine
variants only. The heated seats system comprises, two latching switches, a seat relay and heater elements.
The latching switches are located in the fascia. Each switch individually controls its related seat heater elements.
Each switch contains a tell tale lamp to indicate when the seat heaters are active. There is no timer function for the
seat heater operation and the seat heaters will remain active for as long as the switch is latched in and the ignition
is in position II.
The seat heater relay is located in the passenger compartment fuse box and shares its supply and operation with
the front window lift system. The relay receives a permanent battery voltage supply via fusible links 1 and 3 in the
under seat fuse box and fuse 28 in the satellite fuse box. The relay coil is connected to the ignition switch via fuse
7 in the passenger compartment fuse box and an earth point. When the ignition switch is moved to position II, the
relay coil is energised and the contacts close. Power is supplied from the relay to each of the seat heater
switches.
The heater elements are fitted in the seat cushion and squab on the drivers and passenger front seats and are
wired in series. The wiring looms for the elements is long enough to allow the seat squab to be lifted for access to
the under seat fuse box or the storage bin/battery without straining the wiring. The centre seat, if fitted, does not
have heater elements.
The cushion element receives the feed from the switch and contains a thermostatically controlled switch. When
the element temperature reaches 37±3°C (98±3°F) the thermostat cuts the supply to the cushion and squab
elements for that seat. As the temperature of the element falls to 28±3°C (82±3°F), the thermostat will close the
switch contacts allowing power to flow to both elements causing them to heat up again. In this way the thermostat
maintains the cushion and squab element temperatures between the figures stated.
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Page 634 of 667

ELECTRICAL
25
DESCRIPTION AND OPERATION Electric window lift is a new feature for 02MY. The electric windows are only available on the front driver and
passenger doors. Rear passenger doors retain the manual window lift regulator mechanism.
The window lift system comprises a window motor in each front door, two window lift switches located in the fascia
switch panel and a relay, located adjacent to the passenger compartment fusebox. The windows are only
operative when the ignition switch is in position II.
Each window lift motor is located in the door, behind the trim casing. The motor and regulator form a handed
assembly and are not available separately as serviceable items.
The window lift relay receives a permanent battery feed via fusible links 1 and 3 in the under seat fuse box. The
relay coil has one side connected to earth with the other side receiving a feed from the ignition switch position II.
When the ignition is in position II, the relay is energised and battery voltage is supplied to each of the window lift
switches. On vehicles with heated seats, the relay is shared with the heated seat circuit.
Each switch has two wires to its applicable motor. When the switch is operated in either the up or down position,
one wire is supplied with a feed and the other is connected to earth as applicable for the selection made.
Each motor has thermal cut-out protection. If the window reaches the top or bottom limit of its travel or an object
obstructs the window, the thermal cut-out will sense the increased load on the motor and cut the power supply to
the motor brush contacts.
The cut-out time is between 3.5 to 5.0 seconds, with a time to restart of between 1 to 10 seconds. These figures
are based on an ambient temperature of 20°C (68°F) and a voltage of 13.5V.
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Page 635 of 667

86ELECTRICAL
26
DESCRIPTION AND OPERATION PASSENGER COMPARTMENT FUSE BOX
FROM 02MY
The increase in electrical systems on Defender 02MY vehicles has necessitated an increase in the number of
fuses required.
The passenger compartment fuse box now contains three rows of fuses instead of the previous two rows and
relays to control the CDL system, heated front screen, headlamps, anti-theft alarm ECU and seat heaters and
window lift system.
1.Fuse 8 - Anti-theft alarm ECU/BBUS (10A)
2.Fuse 9 - Front wiper motor and washer pump
(15A)
3.Fuse 10 - Rear wiper relay (10A)
4.Fuse 11 - ABS ECU (10A)
5.Fuse 12 - Engine Control Module (10A)
6.Fuse 13 - Brake pedal switch (10A)
7.Fuse 14 - Reverse lamp switch/Glowplugs (10A)
8.Fuse 15 - Miscellaneous relay control. See
Electrical Library (5A)
9.Fuse 16 - Cigar lighter/Heater blower (20A)
10.Fuse 17 - Radio (5A)
11.Fuse 18 - LH side lamps/trailer pick up (10A)
12.Fuse 19 - RH side lamps/trailer pick up (10A)
13.Fuse 20 - Headlamp levelling/Illumination (10A)
14.Fuse 21 - Direction indicators (10A)
15.Fuse 22 - RH headlamp dip beam (10A)
16.Fuse 23 - LH headlamp dip beam (10A)
17.Fuse 24 - RH headlamp main beam (10A)
18.Fuse 25 - LH headlamp main beam (10A)19.Fuse 26 - Rear fog lamp ECU (10A)
20.Fuse 27 - Alarm relay (10A)
21.Fuse 28 - Air conditioning blower relay (30A)
22.Fuse 29 - Air conditioning compressor
relay/cooling fan relay (20A)
23.Fuse 30 - Interior lamps/radio/alarm
LED/clock/diagnostic socket/tachometer (South
African vehicles only) (5A)
24.Fuse 31 - Hazard warning lamps (15A)
25.Fuse 32 - Heated rear window (20A)
26.Fuse 33 - Seat heat relay (20A)
27.Fuse 34 - RH window lift switch (20A)
28.Fuse 35 - LH window lift switch (20A)
29.Fuse 36 - Heated front screen (30A)
30.Relay - Heated Front Screen
31.Relay - Starter motor
32.Relay - Heated Rear Window
33.Relay - Headlamps
34.Relay - Anti-theft alarm
35.Relay - Seat heat/window lift
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Page 636 of 667

ELECTRICAL
27
DESCRIPTION AND OPERATION UNDER SEAT FUSE BOX
FROM 02MY
1.A/C Relay (if fitted)
2.A/C relay (if fitted)
3.Glow plug relay
4.Main relay
5.Fuel pump relay
6.ABS Return pump relay
7.Fuse 7 - Central Door Locking (CDL) and BBUS
(20A)
8.Fuse 6 - Anti-theft alarm ECU (15A)
9.Fuse 5 - Main relay (30A)10.Fuse 4 - Fuel pump relay (20A)
11.Fuse 3 - Horn/HRW relay (20A)
12.Fuse 2 - Accessory socket (20A)
13.Fuse 1 - ABS ECU (30A)
14.Fusible link 6 - Lights (30A)
15.Fusible link 5 - Ignition switch/Starter relay (60A)
16.Fusible link 4 - ABS Pump relay (30A)
17.Fusible link 3 - Window lift/Seat heat relay (60A)
18.Fusible link 2 - Air conditioning (60A)
19.Fusible link 1 - Glow plugs/Heated front screen
(100A)
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