Range Rover P38
86
ELECTRICAL
NEW RANGE ROVER
16
DESCRIPTION AND OPERATION
Main Beam and Headlamp Flash
There are two main beam outputs to each headlamp
unit. One output operates a main beam only halogen
bulb located in the driving lamp on the inner side of
the headlamp unit. A second output operates a
dip/main beam halogen bulb located in the outer side
of the headlamp unit.
The headlamp main beam and flash function is
operated by pulling the direction indicator stalk
backwards. Two non-latching momentary switches
operate the main beam and flash function, with each
switch providing a momentary earth path to the BeCM
when operated. A short pull backwards operates the
flash switch and a further pull operates the main beam
switch. When the main beam and flash function is
active, a warning lamp in the instrument pack is
illuminated.
When the stalk is pulled to operate the flash switch,
the BeCM will activate the main beam and driving
lamp outputs for as long as the switch is held. When
the switch is released, the switch contact closes and
the BeCM deactivates the main beam and driving
lamp outputs. If the dip beam headlamps and the front
fog lamps are operative, the BeCM will only activate
the main beam. With any other combinations of lamps
the BeCM will operate both the main beam and driving
lamp outputs.
When the stalk is pulled to operate the main beam
switch, the BeCM will activate the main beam and
driving lamp outputs and de-activate the dip beam
headlamp output. When the stalk is pulled a second
time, the second operation of the main beam switch
signals the BeCM to de-activate the main beam and
driving lamp outputs and re-instate the dip beam
headlamp output.
Headlamp Delay
The BeCM has a headlamp delay function to
illuminate the driveway after leaving the vehicle. The
headlamp will operate on dip or main beam depending
on the selected position on the column stalk switch.
The headlamp delay is operated by turning off the
ignition and removing the key with the headlamps on.
When the lighting switch is turned to the off position
quickly, with a dwell of less than 1 second in the
parking/side lamp position, a 25 second headlamp
delay period will be activated by the BeCM.
The delay, when active, can be cancelled at any time
by inserting the key in the ignition, moving the lighting
switch to the parking/side lamp position or the
headlamp position.
Direction Indicators and Hazard Warning Lamps
The direction indicators and the hazard warning lamp
switches, when operated, each complete an earth
path to the BeCM. The BeCM interprets the earth path
completion as a request for indicator operation and
provides power outputs to either left or right hand
direction indicators or the hazard warning lamps.
The BeCM outputs are driven by Field Effect
Transistors (FET). The FET’s detect the continuity of
the indicator lamp circuits (except the side repeater
lamps). In the event of a bulb failure or a short or open
circuit, the break in continuity in that circuit is sensed
by the BeCM.
The BeCM will operate the applicable, or both in the
case of hazard warning lamps, instrument pack
direction indicator warning lamps at double speed.
The BeCM also generates a ’FRONT or REAR
INDICATOR FAILURE’ message in the message
centre. This message is displayed alternately with a
’BULB FAILURE’ message.
Direction Indicators
The direction indicators are operated from the
direction indicator stalk located on the left hand side of
the steering column. Pushing the stalk downwards
activates the left hand direction indicators and pushing
the stalk upwards operates the right hand direction
indicators. The direction indicators operate only with
the ignition in position II.
Two direction indicator warning lamps are located in
the instrument pack. When the direction indicators are
selected, the applicable left or right warning lamp
flashes and the instrument pack emits an audible ’tick’
in time with the pulsed operation of the lamps. The
direction indicators and the audible ’tick’ operate at a
frequency of 1.3 Hz.