Just bought a 2008 STX and the Horn does not work. Fuse us OK what to check next?

 

Some horns will start to work if you give them a little help in the form of a rap , others if exposed to a lot of moisture will need to be replaced. There are some that have an adjustment screw on top and if you manage to turn that screw in both directions will start to work. Some horns are so well hidden you have to play detective to find them.
The horn pad in the vehicle when depressed will complete the ground for the horn relay to work and provide power to the horn(s). What you might try is to confirm power is getting to the horns using a test lite or voltmeter. If power is present then the problem is with the horn itself. If no power, need to locate the horn relay in the relay panel, shown in owner's manual, and confirm if relay clicks when horn pad is depressed if it does then everything is good from the pad inside to the relay.
A little reminder,,, stuff a rag into the horn(s) before working on them , they can get pretty loud and annoying if you are close by and they start working. You will definitely hear them even with a rag stuffed in them.