1. Check the fuse. The horn and radio control are both powered by the same fuse, so if one of them isn't working, it's possible that the fuse is blown. The fuse is located in the fuse box under the hood. Check the fuse and replace it if necessary.
2. Check the horn relay. The horn relay is responsible for sending power to the horn. If the relay is faulty, the horn won't work. The horn relay is located in the fuse box under the hood. Check the relay and replace it if necessary.
3. Check the clockspring. The clockspring is a spiral cable that connects the steering wheel to the rest of the car's electrical system. If the clockspring is damaged, it can cause the horn and radio control buttons on the steering wheel to stop working. The clockspring is located behind the steering wheel. Check the clockspring and replace it if necessary.
4. Check the wiring. If the fuse, relay, and clockspring are all in good condition, the problem may be with the wiring. Check the wiring for any loose, damaged, or corroded connections. Repair any damaged wiring as necessary.
If you're not comfortable troubleshooting these issues yourself, you can take your car to a qualified mechanic for diagnosis and repair.
