Just before the old forum crashed I posted that the horn on my Westy was constantly sounding. After a bad day trying to fix it without sucess my intention was to fit a switch/button on the dashboard. Within minutes I had useful replies saying it was fixable and likely to be a problem at the bottom of the steering shaft/tube. Someone even sent a link to Bentleys manual, most useful. I had another go at it, removing the steering wheel, the plate on the floor at the bottom of the tube and lifting up the tube. As predicted the wire had worn through about half an inch from the terminal and was earthing out. It was a bit of a fiddly fix but is now totally sorted . I'd just like to thank everyone who gave advice and stopped me cutting holes in my unmolested dashboard. If your reading this because you've got a similar problem than it would seem that the bottom of the steering tube is a common problem. Once again thanks for the advice, just shows that the forums work. Malcolm.
Top job! Bleaty horns are easy to fix - better than drilling another hole in your dash (and you'd still have to find the right wires).