How the lights work at the MGF & MGTF

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LH and RH headlamp units contain individual bulbs for headlamp main and dipped beams, and for the side lamps. Tail lamp bulbs are incorporated into the tail lamp units. Rear number plate illumination is provided by two lamps installed in the rear bumper. Operation of the headlamps and side lamps is controlled by a lighting switch in the steering column LH stalk.
A ílights oní alarm is installed to prevent the lights being inadvertently left on when the vehicle is parked.

How it should operate:
Power supplies
Fuse 7 in the under bonnet fuse box supplies a permanent feed to the multi function ECU (MFU) on a Purple-Brown wire.
Fusible link 1 in the under bonnet fuse box supplies two permanent feeds to the lighting switch on brown wires. Fusible link 4 in the under bonnet fuse box supplies a permanent feed to the ignition switch on a Brown-Purple wire. When the ignition switch is turned to position II, the feed is supplied to fuse 1 in the passenger compartment fuse box on a Black-Yellow wire. Fuse 1 supplies the feed to the multi function ECU (MFU) on a Green wire.

Side lamps
Turning the lighting switch to the side lamps position connects a feed from the lighting switch to fuses 7 and 8 of the passenger compartment fuse box on Red wires. Fuse 7 feeds the RH side lamp and the RH tail lamp on Red-Orange wires. Fuse 8 feeds the LH side lamp, LH tail lamp, LH rear number plate lamp and RH rear number plate lamp on Red-Black wires.
All of the lamps are earthed on Black wires and illuminate.

Headlamps
Dipped beam
Turning the lighting switch to the headlamps position operates the side lamps as detailed above and also connects a feed from the lighting switch to fuses 10 and 11 of the passenger compartment fuse box on a Blue-Pink wire. Fuse 10 feeds the LH headlamp dipped beam on a Blue-Pink wire. Fuse 11 (C0585) feeds the RH headlamp dipped beam on a Blue-Black wire. Both headlamp dipped beams are earthed on the same Black wires as the side lamps and illuminate.

Main beam
Selecting main beam connects a feed from the lighting switch to fuses 21 and 22 of the satellite fuse box on a Blue-White wire. Fuse 21 feeds the RH headlamp main beam on a Blue-Green wire. Fuse 22 feeds the LH headlamp main beam on a Blue-Slate wire. Both headlamp main beams are earthed on the same Black wires as the
side lamps and illuminate.

Main beam flash
Operating the main beam flash bypasses the main beam contacts in the lighting switch and operates the main beam circuits as detailed above. When the switch is released the circuit is broken and the headlamp main beams are extinguished.

Lights on alarm
The multi function ECU (MFU) operates an integral warning sounder if the lights are on with the ignition off and the driverís door open.
When the side lamps or headlamps are on, the multi function ECU receives a feed from fuse 8 of the passenger compartment fuse box on a RB wire. When the ignition switch is in position II, the multi function ECU receives a feed from fuse 1 of the passenger compartment fuse box on a Green wire. When the driverís door opens, the Purple-White wire (LHD models) or Purple-Slate wire (RHD models), between the multi function ECU and the driverís door lock motor, is connected to earth on the Black wire between the driverís door lock motor and an earth point (on LHD models) or earth header (on RHD models). While the driverís door is open, if the side lamps or headlamps are on and the ignition switch is not in position II, the multi function ECU switches the warning sounder to earth on a Black wire connected to an earth header and the warning sounder operates.

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