What are the reasons for the Passat horn not working?

[LeReid]

The reasons for the Passat horn not working are as follows: 1. Open circuit in the horn wiring: Use a screwdriver to scrape the "battery" terminal of the horn relay against the ground. If there is no spark, it indicates an open circuit in the live wire, and the wiring from the battery fuse to the "battery" terminal of the horn relay should be checked for any open circuit. 2. Damage to the horn relay: If the live wire has power, use a screwdriver to short-circuit the "battery" and "horn" terminals of the horn relay. If the horn still does not work, it indicates a fault with the horn; if the horn works, it indicates a fault with the horn relay or the button.