A feed from the battery positive terminal is connected by an R wire to the engine
compartment fusebox. The feed passes through fuse 16 and is connected to the contacts
and coil of the horn relay. In this condition the horn relay receives a permanent feed from
the battery.

When one of the horn switches is pushed, an earth path is completed from the horn relay
coil on a PO wire from the engine compartment fusebox, via header C0291 LHD/C0286
RHD, the rotary coupler and horn switches, to earth via fixings E110.
The completed earth path energises the horn relay coil, closing the relay contacts. The feed
from fuse 16 passes through the relay contacts to the LH and RH horns on PG wires causing
the horns to sound.
The LH horn is connected to earth point C0564-1 on a B wire. The RH horn is connected to