Defender Electric Diagrams. Manual - part 20

CIRCUIT OPERATION

DEFENDER 90 NAS

35

CLOCK  

DESCRIPTION  

The analogue clock is located towards the center of the dash panel.  The clock is
illuminated when the sidelights are switched on.  

OPERATION  

Feed from the positive battery terminal is connected to the engine compartment fuse box
(C632-1) by the brown wire.  Current passes through fusible link 1 and fusible link 2 of
the engine compartment fuse box which are connected in series. Fusible link 2 of the
engine compartment fuse box (C574-3) provides a permanent power supply to the
analogue clock (C949-1) on the purple wire.  The clock is grounded (C950-1) on a black
wire.  

Illumination  

The analogue clock has illumination which operates with the sidelights.  Power from
fusible link 1 of the engine compartment fuse box passes through fusible link 4 of the
engine compartment fuse box (C573-2) and feeds the lighting switch (C41-1) on the
brown wire.  The lighting switch (C41-2) is connected to fuse 11 of the passenger
compartment fuse box (C581-1) by the red wire.  When the lighting switch is turned on,
power is supplied through fuse 11 (C581-2) to the dimmer circuit header joint (C285-7)
on the red/black wire - (See interior illumination).  Power flows through the dimmer
circuit (C285-16) to the clock illumination (C948-1) on the red/white wire.  The clock
illumination is grounded on a black wire.  

CIRCUIT OPERATION

36

DEFENDER 90 NAS

CIGAR LIGHTER  

DESCRIPTION  

The cigar lighter is located towards the center of the dash panel. Pressing the center of the
cigar lighter latches the heater element in to the holder. With the ignition switched on,
power flows through the heating element of the cigar lighter, causing it to heat up. When
the heating element reaches a sufficient temperature, the holder automatically releases the
cigar lighter which can then be removed for use.  

The location of the cigar lighter holder is illuminated when the sidelights are switched
on.  

OPERATION  

Feed from the positive battery terminal is connected to the engine compartment fuse box
(C632-1) by the brown wire.  Current passes through fusible link 1 and fusible link 5 of
the engine compartment fuse box which are connected in series. Fusible link 5 of the
engine compartment fuse box (C570-2) is connected to the ignition switch (C026-1) by
the brown wire.  

When the ignition switch is in position  'II', current flows from the ignition switch (C94-1)
to fuse 19 of the passenger compartment fuse box (C581-13) on the white wire.  Fuse 19
(C581-18) is connected to the cigar lighter (C86-1) by the green/orange wire.  The cigar
lighter is grounded (C89-1) on a black wire.  

When the cigar lighter is pressed into its holder, locking clips secure it in position and
also connect the power supply to the heating element.  As the temperature of the heating
element rises, heat is transmitted to the holder, causing the locking clips to expand and
release the cigar lighter at a predetermined temperature.  

Illumination  

The cigar lighter has an illuminated ring which operates with the sidelights.  Power from
fusible link 1 of the engine compartment fuse box passes through fusible link 4 of the
engine compartment fuse box (C573-2) and feeds the lighting switch (C41-1) on the
brown wire.  The lighting switch (C41-2) is connected to fuse 11 of the passenger
compartment fuse box (C581-1) by the red wire.  When the lighting switch is turned on,
power is supplied through fuse 11 (C581-2) to the dimmer circuit header joint (C285-7)
on the red/black wire - (See interior illumination).  Power flows through the dimmer
circuit (C285-16) to the cigar lighter illumination (C74-1) on the red/white wire. The cigar
lighter illumination is grounded on a black wire. 

CIRCUIT OPERATION

DEFENDER 90 NAS

37

IN-CAR ENTERTAINMENT   

DESCRIPTION  

The radio/cassette player operates when the ignition switch is in position I or II.  Signal
output from the radio/cassette player is relayed to four loud speakers via a power
amplifier. The radio/cassette player controls are illuminated when the unit is switched on.
The illumination dims when the sidelights are switched on.  

OPERATION  

Feed from the positive battery terminal is connected to the engine compartment fuse box
(C632-1) by a brown wire.  Current passes through fusible link 1 and fusible link 5 of the
engine compartment fuse box which are connected in series. Fusible link 5 (C570-2) is
connected to  the ignition switch  (C28-1) and fuse 2 of the passenger compartment fuse
box (C580-3) by brown wires.  Fuse 2 (C580-4) of the passenger compartment fuse box
supplies the radio/cassette player (C98-4) with a permanent feed on the purple wire.  The
permanent feed maintains the radio code and pre-set radio channels.  

With the ignition switch in position I or II, power flows through the ignition switch (C99-
1) to fuse 5 and fuse 6 (C580-7) of the passenger compartment fuse box on the
white/orange wire.  Fuse 6 (C580-12) supplies power to the power amplifier (C491/1&2)
on white/light green wires.  Fuse 5 (C580-10) supplies power to the radio/cassette player
(C98-7) on the white/pink wire. The radio/cassette player and power amplifier are
grounded on black wires.  

9 wires connect the radio/cassette player to the power amplifier.  These wires transmit the
audio signals from the radio/cassette player to the power amplifier.  The power amplifier
is connected to the 4 speakers as follows; 
RH front speaker by black/red (C491-14) and black/pink (C491-7) wires,  
LH front speaker by black/orange (C491-13) and black/yellow (C491-6) wires, 
LH rear speaker by black/blue (C491-11) and black/green (C491-4) wires, 
RH rear speaker by black/brown (C491-12) and black white (C491-5) wires.  

CIRCUIT OPERATION

38

DEFENDER 90 NAS

Illumination  

Fusible link 4 of the engine compartment fuse box (C573-2) is connected to the lighting
switch (C41-1) on the brown wire.  With the lighting switch in the on position, power
flows across the switch to fuse 11 of the passenger compartment fuse box (C581-1) on
the brown wire.  Fuse 11 (C581-2) supplies the radio/cassette unit illumination (C98-6)
on the red/black wire.