Fog/Driving Lamp: Description and Operation

FOG LAMPS

DESCRIPTION

General
NAS vehicles incorporate the rear fog lamps within the tail lamp assemblies, where they also double as brake lamps.

All other vehicles have the fog lamps located on either side of the rear bumper, where they operate in the normal manner. Both systems are controlled by the Central Control Unit (CCU). The rear fog lamps will only operate if:
^ The ignition switch is turned to the 'ignition' position.
^ The lighting switch is in the side or headlamp position.
^ The non-latching switch mounted adjacent the instrument pack is pressed.

A warning lamp located in the instrument pack will illuminate when the fog lamps are operational.

OPERATION

General
Feed from the positive battery terminal (C0192) is supplied to fusible link 3, fusible link 9, and fusible link 12 of the engine compartment fuse box (C0192) on an R wire. Fusible link 9 (C0570) provides a constant battery feed to fuse 22 of the passenger compartment fuse box (C0587) on an N wire. Fuse 22 is connected to the rear fog lamp relay, which is also located in the passenger compartment fuse box.

Fusible link 3 (C0571) is connected to the ignition switch (C0028) by an N wire. When the ignition switch is turned to the 'ignition' position, current flows across the switch (C0028) to the rear fog lamp relay and fuse 8 of the passenger compartment fuse box (C0588) on a G wire. Fuse 8 provides an ignition feed to the Central Control Unit (CCU) (C0593), which is mounted directly onto the rear of the passenger compartment fuse box.

The earth path for the fog lamp relay coil is controlled by the CCU (C0593). The CCU (C0592) monitors the condition of the rear fog lamp switch (C0064) by providing a feed via the passenger compartment fuse box (C0589) on a RY wire. When the switch is pressed, a momentary earth path is created on a B wire.

The CCU also monitors the condition of the lighting switch. Fusible link 12 (C0570) provides a constant battery feed to the lighting switch (C0041) on a UN wire. When the lighting switch is turned to the side or headlamp position, current flows across the switch (C0041) to the CCU (C0428) on an OU wire. The CCU will now energise the rear fog lamp relay.