Fuse.
Blown fuse would be a Starting Point. Hope This Helps.
You have to determine the cause first. Check the horn switch and contacts, fuse, relay and the horn itself.
it is the same fuse the horn uses (check it does the horn work?)
fuse
check the fuse
The fuse. A shorted horn can cause the fuse to break.
Get them fixed.
Carry a circus clown in the passenger seat and ask him to honk his horn as required
first remove wire to horn. see if power is going to horn when horn button is pushed. if it does its a horn problem, if not it is probably in the horn button itself.
Check the fuse.
No, they should still work.
Check the actual horn. Clean the contact points and apply dielectric grease to the contact points. Test the horn for resistance. Check the horn relay.