To prevent dazzling oncoming drivers, the headlamps can be adjusted to compensate for the effect of different loads on headlamp vertical alignment. Headlamp levelling is controlled by a four position switch mounted in the centre of the fascia, which operates a levelling motor on each headlamp. Nominal vehicle loads for each switch position are as follows:
- 0 - Driver or driver and front passenger only; no luggage.
- 1 - All seats occupied; no luggage.
- 2 - All seats occupied; full luggage compartment.
- 3 - Driver only; full luggage compartment.
Headlamp levelling operates while the side lamps or headlamps are on.
Operation
Feed from the battery positive terminal is connected to fusible link 6 of the engine compartment fuse box (C0632-1) by a brown wire. Fusible link 6 (C0571-3) is connected to the lighting switch (C0041-1) by a brown/blue wire.
With the lighting switch in either the side or main beam positions, current flows from the switch (C0041-2) to fuse 12 of the passenger compartment fuse box (C0581-1) on a red wire. Fuse 12 (C0581-4) supplies a feed to the LH headlamp levelling motor (C0071-3) and the RH headlamp levelling motor (C0070-3) on red/orange wires.
Fuse 12 (C0581-4) also supplies two feeds to the headlamp levelling switch on red/orange wires. One feed (C0093-5) is used to power the switch illumination bulb, which is earthed (C0093-3) on a black wire. The second feed (C0093-4) supplies current to the switch itself.
At each of the four switch positions, the contacts in the headlamp levelling switch connect to a different resistance value to provide one of four different output voltages. The output voltage (C0093-2) is supplied to the LH (C0071-1) and RH (C0070-1) levelling motors on blue/yellow wires. The LH (C0071-2) and RH (C0070-2) headlamp levelling motors are earthed on black wires. The difference between the voltage from the headlamp levelling switch and battery voltage is then used by electronics in the headlamp levelling motors to set the headlamps to a position corresponding to the switch position.