Did the horn start sounding after you hit the horn button, or did it just
start up on its own? I'm assuming that you hit the button, it started
sounding, but then wouldn't stop.

I'm guessing your 20A fuse blows because the horn has a problem (contact
break set point is out of whack?) When you put an oversize fuse in, the
horn would operate, but you welded the contacts in the horn relay, so now
it won't stop.

If I'm right, then rap on the case of the relay and the contacts may
release. If so, then replace the relay, and either fix, or replace the
horn. Some horns allow you access to a set screw which sets the distance
the diaphram has to move to break the contact (which is how the horn
sounds). If someone ran over something and it hit the horn, it can get out
of whack, you may or may not be able to re-adjust it successfully.

Good luck,
Arthur

wayne wrote:
> Recently bought a 1990 Accord and fuse was blown for horn.Tried a new 20 amp
> fuse tooted horn and blew that fuse.Tried a 30 amp and was fine .Took the
> car for a drive and horn started tooting and would not stop until i got it
> home and removed fuse.Anyone have any idea of the cause?Thanks in advance.
>
>