Horn not working

Yes. Something that is very common. Get out your wallet. The insane engineers have seen fit to go way beyond hanging an unnecessary computer onto every part of our cars. We used to have a horn switch that turned on a ten-dollar relay that sent current to a pair of horns. On your car, the horn switch sends a specific voltage to the most complicated computer on the car, the instrument cluster. The instrument cluster interprets that as "horn request" and sends a digital signal to the "FEM", Front Electronic Module, which sends current to the horns. The most common cause of a dead horn is the instrument cluster, $850.00. The second most common cause is the FEM. Not sure of the cost of that one. Years ago the most common cause was one shorted horn and a blown fuse, but those days are gone. My fingers are crossed that it is something less-serious on your car.

The best place to start is to use a scanner to see what the instrument cluster is seeing. If there is no indication the horn switch is being pressed, you might suspect the clock spring is coming apart, especially if there is a second symptom of "Air Bag " warning light is on or something else in the steering wheel doesn't work. The clock spring is a wound-up ribbon cable in a plastic housing under the steering wheel. Once the cable starts to come apart, multiple circuits will stop working.

If it comes to that I can help with wiring in a common sense relay, but you will have to figure out what you like for a switch.

Yes. The circuit is pretty simple and can be copied from almost any older car brand and model.

You really cannot check the ribbon cable unless you take the assembly apart. It is much faster to view "Inputs and Outputs" on a scanner. You might check at some local auto parts stores that rent or borrow tools to see if they have one you can use.