I've started this separate Topic, for clarity, but Members should also refer to this Topic,
if the wiring at the Fusebox, as described below, is found to be intact :
Ignition Switch Wiring Failures.( Where a break of certain wires at the Ignition switch can result in this, and other faults ).
Fuse No.6 ( 15A ) of the Rear Fusebox, controls the Horn, Position Lights, Brake Light,
and Top Box Power ( when the Top Box optionn has been fitted ).
Remove the left side panel to access the Fuseboxes.
( Disconnect the Heated Seat Switch if fitted
so the Panel can be placed out of harms way ! ).

Using test equipment, check that Fuse No.6 ( 15A ) is intact.

Next, using a suitable Voltmeter, ( or Bulb and wires ), remove he Fuse and check
that there is Voltage at the Input side of the Fuse ( the side nearest the centre of the bike ).
Main Battery voltage should be present at this terminal with the Ignition OFF :

If Voltage is present at the Input side of the Fuse, and the Fuse is intact,
there should be Voltage present at the Output side of the fuse when the fuse is inserted,
and out via the Orange wire running to the Ignition Switch Multi Plug, and a second wire
coloured Green with a Brown Stripe to the Top Box Power Relay.
The wires underneath the Fusebox are tricky to get at, and need a little careful dismantling.
Take into account that there are permanently LIVE wires entering the Fusebox,
so it is recommended that the Main Battery is disconnected prior to dismantling,
to guard against any inadvertent Short circuits to the frame !
Depress the catch in the side of the twin Relay Housing attached to the Fusebox,
lift the Relays Housing up, and move it out of the way.
If the Heated Rider seat option is fitted, Depress the catch on the side of the connector
just rearwards of the Fusebox, and then lift the Connector socket upwards off its Mounting bracket
and position it out of the way.
The Rear fusebox can then be removed from its bracket - depress the catch and lift the fusebox upwards.
There is not a lot of slack in the wiring loom, but the Fusebox can then be CAREFULLY manoeuvred
around the various brackets until it can be turned upside down to examine the contacts underneath.
The large Brown wire shown below provides Power to the Input side of Fuse No.5,
which is connected via a metal strip to Fuse No.6 ( and others ) as shown.
Check the integrity of the wiring and connections using Test equipment,
and check the wiring loom for any signs of chafing or damage.

If any problems are found with the Fusebox or wiring, a repaiir will be needed -
the Fusebox is integral to the main Harness and is not available as a separate part.
If all is well, refer back to the Ignition Switch Wiring Fault Topic mentioned at the start of this Message.