Horns operation (RHD)

HORNS OPERATION (RHD)

The horn receives a direct earth on the B wire.

Battery voltage is supplied from fuse 21 in the passenger compartment fuse box on a U/P wire to one side of the horn relay coil and contacts. The other side of the relay coil receives an earth on the P/B wire from the horn push switch via different paths dependent on model.

NOTE: On some models, the alarm ECU will also supply an earth path to the horn relay coil on a P/B wire when the integrity of the alarm system is broken.

Non-airbag models When the horn switch is pressed, an earth path is supplied to the horn relay coil on a P/B wire via the slip ring and lighting switch.

Airbag models When the horn switch is pressed, an earth path is supplied to the horn relay coil on a P/B wire via the rotary coupler. In all instances, when the relay coil receives the earth it is energised, switching battery voltage from fuse 21 in the passenger compartment fuse box on the UP wire via the closed contacts of the relay to the horn on the P/Y wire. Since the other side of the horn is connected to earth on the B wire, the horn will sound.