This is a recurring problem for me as well.  I also have an '84 Wolfy Westy.
 
Nothing a little banging doesn't cure!  (combined with switching on/off the ignition)
 
Blake B.
-84Wolfy> Date: Tue, 8 Jan 2008 17:14:02 -0800> From: matt@SNOOKSBAND.COM> Subject: Re: Crazy Horn> To: vanagon@GERRY.VANAGON.COM> > Twice now, and I've only been a Westy owner for a couple of months, the horn> has sounded as I turned the ignition and shortly after the engine started.> It then quit on it's own and didn't act up again. Functions normally> otherwise.> > Matt> '84 Wolfy Westy> > > -----Original Message-----> From: Tobin Copley> Subject: Re: Crazy Horn> > Could be that, but check first that a key from your ignition key ring isn't> slicking into the gap between the steering wheel and steering column, thus> shorting the horn circuit intermitently.> > This is a pretty common problem on loaves; I'm unsure how pervasive it is on> vanagons...