What Causes the Sudden Failure of a Volkswagen Car Horn?
3 Answers
Volkswagen car horn suddenly not working may be due to insufficient battery charge, damaged horn relay or button, or a faulty horn. Below are the related causes: 1. Contact Erosion: Prolonged pressing of the horn can easily cause the horn contacts to erode, creating impedance. This weakens the current through the electromagnetic coil, reducing the electromagnetic attraction force, which fails to attract the armature to drive the diaphragm for normal vibration, resulting in a hoarse sound or even no sound at all. However, when the horn is pressed continuously, if a strong instantaneous current passes through the impedance, it can still function normally, leading to intermittent operation. 2. Poor Sealing Leading to Moisture: Although the horn is internally sealed, if the sealing is not tight, moisture may enter during car washing, or water vapor may be present in the internal air space. This moisture can easily cause the contacts to become damp and fail to operate properly. 3. Poor Contact at Electromagnetic Coil Terminals: In some horns, the enameled wire terminal connections of the internal electromagnetic coil are made with aluminum metal rivet crimping instead of secure soldering. If the insulating paint on the wire ends is not properly removed or the rivet crimping is not secure, it can easily lead to a loose connection fault, causing the horn to malfunction. This type of fault is due to the horn's quality issues and cannot be repaired; only replacement with a new part is possible.
Last time I encountered a non-functioning horn, I went straight to the repair shop. The mechanic told me that Volkswagen models typically have several possible causes for horn issues. The most common one is poor contact at the horn contact points inside the steering wheel, which requires disassembling the steering wheel to clean the contacts. Another possibility is a burnt-out horn relay, which can be found in the fuse box. Short circuits in the wiring are also frequent, especially after rain when the wiring tends to get damp, leading to poor contact. For some older cars, the horn itself might be faulty—these parts are actually quite prone to failure. At the time, the mechanic first used a multimeter to test the wiring and found that the relay was burnt out. Replacing it with a new one, which cost just a few dozen yuan, fixed the problem. The mechanic suggested checking the fuse first in such cases, located in the fuse box on the lower left side of the steering wheel.
I can speak with authority on this, having just gone through it. When a Volkswagen's horn suddenly stops working, it's most likely an electrical system issue. Focus on three key areas: the metal contact in the horn button often oxidizes, causing poor contact - this is particularly common; then check the fuse, as older cars tend to blow fuses; finally inspect the relay, that small square box in the engine compartment's fuse box. Last time my car's horn suddenly stopped working, it turned out mice had chewed through the wiring, which was quite troublesome to repair. Another diagnostic trick is to listen - if you hear a clicking sound when pressing the horn, it means the relay is activating and the horn itself is faulty; if there's no sound at all, then it's a wiring or button issue. If attempting DIY repairs, remember to disconnect the battery first - safety comes first.
