Originally Posted by maviczap

Remove horn terminals and plug into relay. make up a wire and connect one end to positive battery terminal, the other end to the correct terminal on the relay, another from the - terminal on the battery to the negative on the horn, but just as easy to find a place on the frame to earth it to.

Then from the relay make up two wires to the horn connection, one + & one -

Secure relay somewhere, I hid mine under the tank

Thats how I did mine, others may have an easier solution

The horn button on the LH switchgear activates the relay and allows power to go to the horn, but protects the Sv wiring

Yes, you can get everything you need at Halfrauds, my Stebel came with a relay.

Sounds difficult, but it isn't