The horn itself is faulty....remove it You will see rust around the base of the horn There is a green area with rivets in it these will be rustes causing the horn to be inop....That or the orange wire to the horn is poinched and broken about 4-6 inches from the horn connector
You have a loose wire, blown fuse or a faulty horn.
It could be the relay or the fuse or the horn itself. Or, it could be all three!
Check the fuse?
I just had this problem, the fuse is in position 11 in fuse box, 25 amp, mine read HDLP on fuse box. Both the daytime headlights and horn on same fuse.
Start by checking the fuse.
On my 2004 Jeep Liberty the power windows and the horn relay are powered by the front power outlet fuse. use at least a 20 amp fuse.
Could be the fuse.
there is a fuse for it check to see if it is blown
Your problem is a fuse in the engine compartment nearest to the front, its a plastic black box. The fuses are for AC fans and the horn and some others in there.
Your temperature sensor or a fuse is bad.
Check the fuse/circuit breaker. If they check okay you may have a mechanical problem.
i bought new horn for my nissan almera 5 door hatch back 1500cc and still wont work and checked fuse