DESCRIPTION AND OPERATION
4.2
DEFENDER 1999 MY
OPERATION
The battery positive terminal provides a feed to the engine compartment fuse
box (C0632-1) on a brown wire. Fuse 6, fuse 7, fusible link 5 and fusible link 6
are all connected in parallel and provide a direct battery feed to the following;
•
Fuse 6 (C0574-2) provides two feeds to the alarm ECU on purple/brown
wires. The first (C0061-25) is used as a power signal. The second
(C0057-8) is used to power the indicator lamp circuits (C0057-1 & C0057-6)
on green/white (RH indicators) and green/red (LH indicators) wires
respectively.
•
Fuse 7 (C0574-1) provides a feed to the front interior lamp (C0355-3) on a
purple/brown then purple wire.
•
Fusible link 5 (C0570-2) provides a feed to the BBUS (C0666-2) on a brown
then black wire, and the ignition switch (C0028-1) on a brown/white wire.
•
Fusible link 6 (C0571-3) provides feeds to the alarm relay (C0731-6 &
C0731-8) on brown/blue wires, and the alarm LED (C1060-6) also on a
brown/blue wire.
The alarm ECU receives arm and disarm commands from the RF handset via
an aerial. The aerial (C1136-1) is connected to the alarm ECU (C0061-26) by a
orange/slate wire. When the alarm ECU is disarmed and the ignition switch is
set to the crank position, it provides an earth path (C0057-10) for the starter
relay (C0151-6) on a black/orange wire. This will enable the engine to be
started.
See Charging and Starting.
The Alarm ECU (C0061-14) also communicates with the ECM (C0658-34). It
sends a pulsed voltage signal along a light green/slate wire to control engine
immobilisation. The alarm ECU (C0057-12) also sends a constant battery feed
to the passive coil (C0049-2) on an orange/purple wire. A second pulsed
voltage signal is sent by the alarm ECU (C0057-7) to the passive coil
(C0049-1) on an orange/green wire.
See Engine Immobilisation.