Land Rover Discovery 99my To 03my Electrical Library 3rd Edition Rover Manual

DESCRIPTION AND OPERATION
4.110DISCOVERY SERIES II
HEADLAMP LEVELLING
DESCRIPTION
General
The headlamp levelling is operated from a four position switch located on the fascia. The 
switch operates a motor located in each headlamp unit which moves the headlamp position 
to allow for changes in vehicle attitude due to load or passenger distribution.
The headlamp levelling operates when the side lamps or headlamps are on and is 
independent of the ignition switch position.
OPERATION
Headlamp Levelling...

DESCRIPTION AND OPERATION
DISCOVERY SERIES II 4.111
Headlamp Levelling Operation
At each of the four headlamp levelling switch positions, the contacts in the switch connect 
through resistors with differing values, which in turn provide four differing output voltages.
The output from the headlamp levelling switch is on a UY wire to header C0293 LHD/C0289 
RHD. The output is connected from header C0293 LHD/C0289 RHD on UY wires to both 
headlamp levelling motors. The headlamp levelling switch is connected...

DESCRIPTION AND OPERATION
4.112DISCOVERY SERIES II
LIGHTS ON ALARM
DESCRIPTION
General
The lights on alarm in the instrument pack operates when the drivers door is open and the 
side lamps are on. The system uses inputs from:
zThe drivers door switch
zThe lighting switch
A serial data bus allows communication between the the Body Control Unit (BCU), the 
Intelligent Driver’s Module (IDM) and the instrument pack.
OPERATION
Lights On Alarm Supply
Circuit supply
A feed from the battery positive terminal is...

DESCRIPTION AND OPERATION
DISCOVERY SERIES II 4.113
The IDM is connected on the serial data bus link to pin C0661-1 on the BCU, and to the 
instrument pack via header C0293 LHD/C0292 RHD by an SK wire. When the drivers door 
is opened, the door switch contacts close, current flows from fuse 13 on a PN wire to pin 
C0660-13 on the BCU. From pin C0660-17 on the BCU the current flows on a PW wire via 
header C0287 LHD/C0285 RHD to the closed contacts of the drivers door switch. From the 
closed contacts of...

DESCRIPTION AND OPERATION
4.114DISCOVERY SERIES II
HEAD/SIDE AND NUMBER PLATE LAMPS
DESCRIPTION
General
The side lamps, headlamps and number plate lamp are all controlled from a rotary lighting 
switch located on the column indicator lever. The side lamps and headlamps receive a 
permanent supply from the battery and operate independently of the ignition switch.
Two front headlamps contain the side lamp, dip and main beam bulbs. The side lamp bulbs 
are rated at 5 Watts. The dip beam bulbs are rated at...

DESCRIPTION AND OPERATION
DISCOVERY SERIES II 4.115
Side and Number Plate Lamps Operation
When the lighting switch is moved to the side lamps position, the feed from fusible link 12 in 
the engine compartment fusebox, passes through the switch contacts. The feed is 
connected on an R wire to the passenger compartment fusebox, where it passes through 
fuses 11 and 33.
When the lighting switch is moved to the headlamp position, the feed from fusible link 12 to 
the front and rear side lamps is maintained....

DESCRIPTION AND OPERATION
4.116DISCOVERY SERIES II
RH front side lamp
From the header C0289 LHD/C0290 RHD, a feed is connected on an RO wire to the RH 
front side lamp. The earth path from the RH front side lamp is on a B wire, via splice joint 
SJ3 to earth eyelet connector C0559-1.
RH tail and rear side marker lamps
A feed is taken from header C0289 LHD/C0290 RHD on an RO wire to header C0723. The 
feed continues from header C0723 on a RO wire to the RH tail lamp and the RH rear side 
marker lamp. The...

DESCRIPTION AND OPERATION
DISCOVERY SERIES II 4.117
Headlamps - Main Beam Operation
When the lighting switch is moved to the flash or main position, the feed from fusible link 10 
in the engine compartment fusebox, passes through the switch contacts. The feed is 
connected on a UW wire to the passenger compartment fusebox, where it passes through 
fuses 3 and 22.
The IDM senses the headlamp main beam request and through internal circuitry, provides 
a feed, on a US wire, to the main beam warning lamp in...

DESCRIPTION AND OPERATION
4.118DISCOVERY SERIES II
FRONT FOG LAMPS
DESCRIPTION
General
The front fog lamps are controlled by a non-latching switch located on the left hand side of 
the instrument pack. Two front fog lamps are located below the front bumper. Front fog lamp 
operation is monitored by the Body Control Unit (BCU) which only allows the front fog lamps 
to operate when the side lamps or headlamps are on.
When the side lamps, headlamps or ignition is turned off, the front fog lamps are...

DESCRIPTION AND OPERATION
DISCOVERY SERIES II 4.119
Ignition switch supply
With the ignition switch in position I, the feed from fusible link 8 flows through the ignition 
switch to the passenger compartment fusebox on a LGW wire. The feed continues through 
fuse 26 in the passenger compartment fusebox and is connected by an LG wire to the 
engine compartment fusebox and the coil of the auxiliary circuits relay. The auxiliary circuits 
relay coil is connected to earth header C0018, via header C0286...