The system for the horns is supplied through the horn relay R3 , located in engine compartment junction unit B01 from the direct line from the battery through the fuse F10 located in the junction unit.The coil of the relay R3 is energized by an earth signal when one of the steering switches is closed; on versions with Air Bags these connections are made via the clock spring at the steering column switch unit H05 .This signal reaches pin 21 of connector B of engine compartment junctionunit B01.The relay R3 supplies the horn P05 from pin 28 of connector B.The horn P05 and the steering column switch unit H05 are connected to earth C10 at pins 2 and 16, respectively.