Land Rover Defender V8i Electrical Library Rover Manual

							DESCRIPTION AND OPERATION
4.20
DEFENDER V8i
Fuse 17 (C581-14) supplies a feed to the blower relay coil (C817-86) on a
green wire, and the compressor clutch relay coil (C1213-86), also on a green
wire. The blower relay coil (C817-85) is earthed on a black wire. The earth path
for the compressor clutch relay coil (C1213-85) is controlled by the ECM
(C634-1), which is connected to the relay by a blue/black then black/slate wire.
The now energised blower relay (C817-87) allows current to flow to the blower
motor switch (C275-5) on a brown wire. The blower motor switch is a 3 position
switch. Slow speed is attained by turning the switch to position 1. A feed can
now flow from the switch (C275-3) to the blower motor (C848-1) on a blue wire.
As the current has to flow through the 2 in-line resistors before reaching the
motor itself, a slow motor speed is attained. The motor is earthed (C1215-1) on
a black wire.
Turning the blower switch to position 2 allows a feed to flow from the switch
(C275-1) to the blower motor (C844-1) on a green wire. As the current now
only has to flow through 1 in-line resistor, a medium speed is attained.
For high speed operation, turning the blower switch to position 3 (C275-2)
allows current to flow direct to the motor (C845-1) on a red wire without having
to flow through the in-line resistors. As in the case of low speed and medium
speed operation, the blower motor (C1215-1) is earthed on a black wire.
Once the blower motor switch has been turned to position 1, it also allows
current to flow (C275-4) to the interlock relay coil (C153-4) on a blue/yellow
wire. The relay coil is earthed (C153-2) on a black wire. The interlock relay is
also energised when the blower switch is in position 2 and 3.
Although the blower will operate with the ignition on, the air conditioning system
itself will not operate until the engine is running, and a number of conditions are
met. 
						

							DESCRIPTION AND OPERATION
DEFENDER V8i4.21
Fuse 7 of the engine compartment fuse box (C574-1) supplies a feed to the
main relay coil within the engine management relay module (C154-6) on a
brown/light green wire. If the engine is running, the ECM (C635-17) provides an
earth path for the main relay (C157-3) on a blue/red wire. This energises the
main relay and allows a feed (C154-3) to flow to the condenser fan relay coil
(C1212-85) on a brown/orange then slate/blue wire.
The earth path for the condenser fan relay (C1212-86) is again controlled by
the ECM (C634-3), this time on a slate/black then green/white wire. This
energises the condenser fan relay, and allows the feed from fuse 16 of the
passenger compartment fuse box (C581-12) to flow across the relay (C1212-30
& C1212-87) and onto the condenser fan (C280-1) on a blue/purple wire. The
condenser fan is earthed (C280-2) on a black wire.
The compressor will only operate if a number of conditions are met, and is
controlled by the compressor clutch. The clutch will only allow the compressor
to operate if:
·The engine is running.
·The refrigerant pressure in the high pressure line is within the set limits.
·The temperature within the system is within the set limits.
·Excessive engine temperatures are not reached.
Assuming all these conditions are met, the compressor clutch relay will be
energised by the ECM. Current will flow from the relay (C1213-87) to the
compressor clutch (C182-1) on a brown/pink wire. The clutch is earthed
(C182-2) on a black wire. This engages the compressor clutch and drives the
compressor. 
						

							DESCRIPTION AND OPERATION
4.22
DEFENDER V8i
HEATER BLOWER
DESCRIPTION
The heater is operated by three sliding controls attached to the instrument
binnacle. Two of the controls regulate the temperature and air flow distribution.
The third control operates the two speed heater blower. The heater blower
operates with the ignition switch in position I, and is completely independent of
the air conditioning system.
OPERATION
Feed from the positive battery terminal is connected to the engine compartment
fuse box (C1217-1) by a brown wire. Current passes through fusible link 5
(C570-2), which is connected to the ignition switch (C28-1) by a brown wire.
With the ignition switch in position I, power flows across the switch (C99-1) to
fuse 4 (C580-7) of the passenger compartment fuse box on a white/orange
wire. Fuse 4 (C580-8) then supplies a feed to the blower motor (C431-3) on a
purple/green wire. When the blower switch is in the Off position, the blower
motor has no route to earth and does not run.
Moving the blower switch to position I, connects the blower motor (C431-2) to
the blower switch (C58-2) on a green/yellow wire. Power flows through the
blower motor and resistor to the switch, which is earthed (C58-3) on a black
wire. The blower motor will now operate at low speed.
Moving the blower switch to position II, connects the blower motor (C431-1)
directly to the blower switch (C58-1) on a green/slate wire. Again, the switch is
earthed (C58-3) on a black wire. The blower motor now operates at high
speed. 
						

							DESCRIPTION AND OPERATION
DEFENDER V8i4.23
HEATED REAR WINDOW (HRW)
DESCRIPTION
The heated rear window (HRW) is operated by a latching switch mounted on
the dash panel. When the switch is set to the On position, the instrument
panel warning lamp will illuminate to indicate the HRW is operating. The HRW
only operates when the ignition switch is turned to position II.
OPERATION
Feed from the positive battery terminal is connected to the engine compartment
fuse box (C1217-1) by a brown wire. Current passes through fusible link 1 and
fusible link 5, which are connected in parallel. Fusible link 5 (C570-2) is
connected to the ignition switch (C28-1) by a brown wire.
Fusible link 1 is connected in series with fuse 3. Fuse 3 (C571-1) supplies a
feed to the heated rear window relay switch (C44-87) on a brown/slate wire.
With the ignition switch in position II, current flows from the switch (C90-1) to
fuse 1 of the passenger compartment fuse box (C580-1) on a white wire. Fuse
1 (C580-2) is connected to the heated rear window switch (C72-4) by a
white/green wire. When the switch is depressed, current is allowed to flow
across the switch (C72-2) and energise the heated rear window relay (C44-85
& C44-86) on a white/green wire. The relay is earthed on a black wire.
The energised relay (C44-30) now allows current to flow to both the heated
rear window (C381-1) and the instrument pack warning lamp (C1051-1). The
instrument pack warning lamp (C1050-1) is earthed on a black wire. 
						

							DESCRIPTION AND OPERATION
4.24
DEFENDER V8i
WIPERS AND WASHERS
DESCRIPTION
The front windscreen wipers are controlled from the column switch and operate
when the ignition switch is in position II. The wipers have 2 speed settings,
along with a flick wipe and single wipe facility. An intermittent wipe function and
programmed wash wipe facility is controlled by the front wiper delay unit.
Moving the wiper switch down from the off position initiates the intermittent
wipe function. Moving the wiper switch up one position from the off position,
operates the wipers at slow speed. Moving the wiper switch up two positions
from the off position, operates the wipers at fast speed. Pushing the wiper
switch up from the off position, not allowing it to latch, and then releasing it
causes the wipers to perform a single wipe cycle at slow speed. Pushing and
holding the wiper switch up from the off position, not allowing it to latch, causes
the wipers to operate at slow speed until the wiper switch is released.
Pressing the end of the wiper switch, initiates the programmed wash wipe
sequence. The windscreen washers operate while the switch is pressed and
the wipers continue to operate for a number of cycles after the switch is
released.
The rear screen wiper and wash facilities are controlled by a switch mounted
on the dash panel. Pressing the switch causes the rear washer to operate until
the switch is released. The rear wiper does not operate automatically with the
rear wiper. Turning the switch clockwise causes the rear wiper to operate until
the switch is turned back to the off position. 
						

							DESCRIPTION AND OPERATION
DEFENDER V8i4.25
OPERATION
Feed from the positive battery terminal is connected to the engine compartment
fuse box (C1217-1) by a brown wire. Current passes though fusible link 5
(C570-2) which is connected to the ignition switch (C28-1) by a brown wire.
With the ignition switch in position II (C90-1), a feed is supplied to fuse 17 and
18 of the passenger compartment fuse box (C581-13) on a white wire. Fuse 17
(C581-14) supplies power to the rear wash/wipe circuit, while fuse 18
(C581-16) supplies power to the front wash/wipe circuit.
Front Wipers and Washers
Fuse 18 of the passenger compartment fuse box (C581-16) supplies the front
wiper relay (C39-8) a feed on a green wire when the ignition switch is in
position II.
Slow and Fast Speeds
Fuse 18 also provides a feed to the wash/wipe switch (C278-6) on a green
wire. Moving the switch to the slow speed position allows power to flow across
the switch (C278-1) to the wiper motor (C30-3) on a blue/light green wire. This
feed into the wiper motor also has to travel through an internal resistor. This
extra resistance causes the motor to operate at slow speed. The wiper motor is
earthed (C30-1) on a black wire.
Moving the wiper switch to the fast speed position allows power to flow through
the switch (C278-5) to the wiper motor (C30-5) on a red/light green wire. This
time the feed from the switch does not have to flow through the internal
resistor, causing the motor to operate at fast speed. Again, the motor is earthed
(C30-1) on a black wire.
Operating the flick wipe function outputs a feed from the wash/wipe switch
(C278-5) and onto the wiper motor (C30-5) for as long as the switch is held
against spring pressure. The wipers operate at fast speed. 
						

							DESCRIPTION AND OPERATION
4.26
DEFENDER V8i
Park Circuit
Positioning the wash/wipe switch to the off position cuts power to the wiper
motor on the blue/light green or red/light green wire. The park circuit operates
to return the wipers to their park position. The park switch (C30-4) is integral to
the wiper motor. It receives a feed from fuse 18 of the passenger compartment
fuse box (C581-16) on a green wire. The park switch is closed with the wipers
in any position other than their park position.
With the park switch closed, power flows across the switch (C30-2) to the front
wiper relay (C39-5) on a brown/light green wire. The front wiper relay (C39-2) is
connected to the wash/wipe switch (C278-4) by a yellow/light green wire.
Power flows through the wash/wipe switch (C278-1) to the wiper motor (C30-3)
on a blue/light green wire. The wiper motor is earthed (C30-1) on a black wire.
The wipers operate until their park position is reached and the park switch
opens, cutting the power supply to the wiper motor.
Intermittent Wipe
Moving the wash/wipe switch to the intermittent wipe position allows power to
flow across the switch (C278-3) to the front wiper relay (C39-1) on a
white/green wire. When this signal is received by the relay, it switches the route
to earth (C39-4) on and off approximately every 5 seconds on a black wire. An
intermittent feed is then supplied from the relay (C39-2) to the wash/wipe
switch (C278-4) on a yellow/light green wire. Power flows through the switch
(C278-1) and supplies the wiper motor (C30-3) on a blue/light green wire. The
wipers operate at slow speed.
Programmed Wash/Wipe
Depressing the end of the wash/wipe switch operates the programmed
wash/wipe function. The washer switch (C278-6) is supplied a feed by fuse 18
of the passenger compartment fuse box (C581-16) on a green wire. When the
switch is closed, power flows across the switch (C278-2) to the front wiper relay
(C39-6) and the windscreen washer pump (C8-2). Both are supplied a feed on
light green/black wires. The washer pump is earthed (C8-1) on a black wire. 
						

							DESCRIPTION AND OPERATION
DEFENDER V8i4.27
When the front wiper relay (C39-6) receives a feed from the wash/wipe switch
(C278-2), it outputs a feed (C39-2) back to the wash/wipe switch (C278-4) on a
yellow/light green wire. Power flows across the wash/wipe switch (C278-1) and
onto the wiper motor (C30-3), which operates at slow speed. When the washer
switch is released, the relay will operate the wipers for a further 3 cycles. Once
this has been completed, feed to the wash/wipe switch is cut by the relay and
the park circuit is initiated.
Rear Wiper
The rear wiper switch (C1197-1) is supplied a feed by fuse 17 of the passenger
compartment fuse box (C581-14) on a green wire. When the switch is in the
on position (C1194-1), power is fed to the rear screen wiper motor (C388-2)
on a red/light green then brown/light green wire. The wiper motor is earthed
(C388-1) on a black wire.
Rear Park Circuit
Positioning the wiper switch to the off position cuts power to the rear wiper
motor on the red/light green then brown/light green wire. The park circuit
operates to return the wiper to its park position. The park switch (C1105-2) is
integral to the wiper motor. It receives a feed from fuse 17 (C581-14) of the
passenger compartment fuse box on a green wire. The park switch is closed
with the wiper in any position except its park position.
With the park switch closed, power flows across the switch (C1105-1) to the
wiper switch (C1195-1) on a brown/light green wire. Power flows across the
wiper switch (C1194-1) back to the wiper motor (C388-2) on a red/light green
then brown/light green wire. The wiper motor is earthed (C388-1) on a black
wire.
Rear Wash
The rear washer switch (C1197-1) is supplied a feed by fuse 17 of the
passenger compartment fuse box (C581-14) on a green wire. When the switch
is depressed power is fed (C1196-1) to the rear screen washer pump (C21-2)
on a black/light green wire. The washer pump is earthed (C21-1) on a black
wire. The rear screen wash does not operate the rear wiper. 
						

							DESCRIPTION AND OPERATION
4.28
DEFENDER V8i
EXTERIOR LAMPS - Brake and Reverse Lamps
DESCRIPTION
The brake lamps illuminate when the ignition switch is in position II and the
brake pedal is depressed. The reverse lamps illuminate when the ignition
switch is in position II and the gear selector lever is in the reverse position.
OPERATION
Feed from the positive battery terminal is connected to the engine compartment
fuse box (C1217-1) by a brown wire. Current passes through fusible link 5
(C570-2) and is connected to the ignition switch (C28-1) by a brown wire.
When the ignition switch is in position II, current flows across the switch
(C90-1) to fuse 18 of the passenger compartment fuse box (C581-13) on a
white wire.
Fuse 18 (C581-16) supplies a feed to both the brake pedal switch (C29-1) and
the reverse lamp switch (C69-2), which are connected in parallel. Both are
supplied on green wires.
Brake Lamps
When the brake pedal is depressed, the brake pedal switch closes and current
flows across the switch. The brake pedal switch (C75-1) supplies a feed to:
·The centre high mounted stop lamp (CHMSL) (C832-1).
·The trailer pick-up (C1146-1).
·The RH brake lamp (C125-2).
·The LH brake lamp (C121-2).
All 4 are connected in parallel and are supplied a feed on green/purple wires,
and earthed on black wires.
Reverse Lamps
When reverse gear is selected, the reverse lamp switch is closed. Current
flows across the switch (C69-3) to the RH reverse lamp (C455-1) on a
green/brown wire. Current flows across the RH reverse lamp (C455-2) and
onto the LH reverse lamp (C472-1), also on a green/brown wire. Both lamps
are connected in series. The LH reverse lamp is earthed (C1190-1) is earthed
on a black wire. 
						

							DESCRIPTION AND OPERATION
DEFENDER V8i4.29
EXTERIOR LAMPS - Head, Side and Number Plate Lamps
DESCRIPTION
The lights are operated from the lighting switch located on the steering column.
The lighting switch has two positions. Position 1 switches on the tail lamps, the
number plate lamps, and the front side lamps. Position 2 additionally switches
on the front headlamps. When the headlamps are on, the column switch can be
used to switch between main beam and dipped beam.
The headlamps can be flashed with the lights on or off, by pulling the column
switch towards the driver.
OPERATION
Feed from the positive battery terminal is connected to the engine compartment
fuse box (C1217-1) by a brown wire. Current passes through fusible link 1,
fusible link 5, and fusible link 6, which are all connected in parallel.
Side Lamps
Fusible link 6 (C572-3) is connected to the lighting switch (C41-1) by a brown
wire. With the lighting switch in position 1, current flows across the switch
(C41-2) to fuse 11 and 12 (C581-1) of the passenger compartment fuse box.
Fuse 11 (C581-2) supplies the LH side of the vehicle, while fuse 12 (C581-4)
supplies the RH side of the vehicle.
Current flows from fuse 11 (C581-2) to the LH front side lamp (C538-2) on a
red/black wire. The side lamp is earthed (C538-1) on a black wire. Connected
in parallel with the side lamp is the trailer pick-up (C1189-1), which is also
supplied a feed on a red/black wire. The trailer pick-up (C1189-2) is connected
in series with the LH tail lamp (C121-3) by a red/black wire. The tail lamp is
earthed (C121-1) on a black wire. Wired in parallel with the LH tail lamp is the
rear number plate lamp (C138-1). Again, current is supplied on a red/black
wire. The lamp is earthed (C1190-1) on a black wire.