The most common problem is a broken clock spring. That is a wound-up ribbon cable in a plastic housing under the steering wheel. As it continues to break, the cruise control will stop working and the air bag light will turn on.
I'm not sure which year they started this silly nonsense but Ford engineers saw fit to involve two unreliable computers in blowing the horn and they've had a huge problem with them. Instead of the common sense horn switch that turned on a ten-dollar relay to blow the horn, the switch now sends a signal to the most complicated computer on the car, the instrument cluster, which interprets that signal, then sends a digital signal to the FEM (front electronic module) which interprets that as a request for the horn so it turns on that horn relay. Typical repair cost on those cars for a dead horn averages $800.00. I'm not sure what problem they found a solution to but it makes them a lot of money.