In reply to a message from rich schofield sent Mon 7 Dec 2015:
I agree with Doug, it should be the horn.
I wonder if the fuse failed sometime and someone has connected the
switch (in the steering wheel pad) directly to the horn by fudging
the connections at the relay. So the switch operates the horn
directly instead of switching a relay?
It might be worth checking the connections to the relay which is
inside the right wing below the air filter near the fuel injector
resistor pack. It should have four connections. 2 thin wires, which
are the switch circuit, and are connected to the relay coil. 2
heavier brown wires one of which comes from that fuse you’ve found,
the other goes to the horn. The latter are connected to the relay’s
The original message included these comments:
I have an inline fuse and holder on the bulkhead in the
engine bay - its on the drivers side ( UK car, rhd ) near
the master cylinder. It contains a 17 amp fuse. It has a
brown cable going to it.
Nearest thing I can see in the handbook is a ‘horn’ fuse
listed as ‘on the bulkhead’ - but the horn still works with
it disconnected !.
Any ideas what circuit it is for ?