The horn P005 receives a power supply via relay T03, located in the engine compartment junction unit B001, via the direct battery line protected by fuse F10 of the same junction unit.The coil for relay T03 of B001 (pin 41 of connector B) is energized by an earth signal when the switch on the steering wheel is closed (pin 8 of the clock spring D047). Pin 7 of the clock spring D047 is connected to the left dashboard earth C015.Relay T03 thereby supplies the horn P005 from pin 39 of connector B of the engine compartment junction unit B001.The horn P005 is connected to the left front earth C010.