For the horn..

Pull the steering wheel cover off, exposing the electricals behind the two buttons. Clean the contacts there,, and make sure the buttons are indeed making contact at all.

If that doesn't fix it, then there is a wiping contact behind the wheel itself. Basically it is a 'giant washer' shaped thin plate of metal, with a spring loaded probe that makes contact with the 'giant washer' in any turning position of the wheel. If you pull your wheel, this will make sense.

I had to install some actual washers behind the three 'giant washer' screws to stick it out further - the metal probe wasn't making contact,, by about 2mm. Clean this conections as well.


good luck,

Scerb