Did you check voltage at the fuse circuit. Goes hot with the key on. Use voltage tester/testlite. The problem is usually the wiring in the steering column. There are safety issues with working on the steering column because of air-bag. The horn button the steering wheel is a ground for the coil side of horn relay. You could use a jumper wire at the horn relay, relay unplugged, use jumper between terminal 30 and 87, the horn should honk, if terminal 30 is hot.