What Are the Reasons for a Car Horn Not Working?
2 Answers
There are three main reasons why a car horn may not work: 1. Contact point erosion: Prolonged use of the horn can cause the contacts to erode, creating resistance. This weakens the current flowing through the electromagnetic coil, reducing the electromagnetic force and preventing it from attracting the armature to vibrate the diaphragm properly, resulting in a hoarse sound or no sound at all. However, when the horn is pressed repeatedly, a strong momentary current can still pass through the resistance, allowing the horn to work intermittently. 2. Poor sealing leading to moisture: Although the interior of the horn is a sealed space, if the seal is not tight, moisture or water vapor can enter during car washing. This moisture can cause the contacts to become damp and malfunction. 3. Poor contact at the electromagnetic coil terminals: Some horns have aluminum rivet connections for the enameled wire terminals of the internal electromagnetic coil instead of secure soldering. If the insulation varnish on the wire ends is not properly removed or the rivet connections are loose, it can lead to poor contact, causing the horn to malfunction. This issue is due to the horn's quality and cannot be repaired; the only solution is to replace it with a new one.
I've encountered quite a few issues with horns not working, and the most common reason is the horn itself being faulty. For example, prolonged use can cause internal contacts to age or deform, preventing current from passing through, which makes the horn stop working. Another major issue is a blown fuse, especially the one related to the headlights in the fuse box under the steering wheel. When the current is too high, it automatically blows to protect the circuit, so you'll need to open it up and check if it's burned out. There's also the problem of worn switch contacts. If there's no response when pressing the horn button, it might be due to a loose connection or dirty internal contacts, which requires cleaning or replacement. A faulty relay is also troublesome, as it controls the current switch. Once it fails, the signal can't be transmitted, and aging or short-circuited wiring can also interrupt the current. In short, if you find your horn isn't working, the first thing to do is check the fuse and use a test pen to test the switch button. If that doesn't work, take it to a repair shop for a comprehensive diagnosis. Don't let these small issues affect your driving safety.
