Horn switch

The horn switch is in the steering wheel airbag the easiest way is with a test light.... when you press the horn, that is a simple switch... assuming you have airbags, start from the horn, (in the engine bay) and work your way back to the switch....(in the cab) take a test light, and when the horn is pressed (in the cab), it should make the test light glow... (this is a 2 person job) if you have power when you press the horn (in the steering wheel), then check the ground on the actual horn itself.... if both are good, replace the horn.

Here is a guide to help you use the test light.

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

Check out the diagrams (Below). Let us know what happens and please upload pictures or videos of the problem.

Cheers