A horn failure can often be traced to an over-rotated steering wheel. This can accidentally happen during a steering rack swap, if the column is not locked during the procedure. The horn, cruise control, turn signal, brights, airbag, and wiper circuits...are all routed thru a fragile ribbon cable inside the steering column. This cable is coiled up inside the smart switch and when it breaks you can loose power to any/all of these devices.
If you have had recent work done to your truck, you may want to check the voltage going to the horn, before replacing it. It might be the wiring and not the horn itself.