1. Blown fuse: The horn fuse may have blown, which would cut power to the horns. Check the fuse box and replace the horn fuse if it is blown.
2. Faulty horn relay: The horn relay is responsible for sending power to the horns when the horn button is pressed. If the relay is faulty, it will not be able to send power to the horns, causing them to not work.
3. Bad horn switch: The horn switch is the button that you press to sound the horns. If the switch is faulty, it will not be able to send a signal to the horn relay, which will prevent the horns from working.
4. Wiring problems: There may be a problem with the wiring that connects the horn switch, horn relay, and horns. If the wiring is damaged or disconnected, it will prevent the horns from working.
5. Faulty horns: The horns themselves may be faulty and no longer able to produce sound.
To troubleshoot the problem, you will need to check each of these components to see if they are working properly. If you are not comfortable doing this yourself, you can take your car to a qualified mechanic to have it diagnosed and repaired.