What are the reasons for the horn not working on a Mercedes-Benz GLK300?

[StElias]

Here are the specific reasons why the horn may not work on a Mercedes-Benz GLK300: Poor contact at the electromagnetic coil terminal: Some horns have internal electromagnetic coil enameled wire terminal connections made with aluminum metal rivets instead of secure welded connections. If the insulation paint on the wire ends is not properly removed or the rivet connection is not secure, it can easily lead to a poor connection, causing the horn to malfunction. This type of fault is due to the horn's quality and cannot be repaired; only a replacement will solve the issue. Contact point erosion: Prolonged use of the horn can cause the contact points to erode, creating impedance. This reduces the current flowing through the electromagnetic coil, weakening the electromagnetic force and preventing it from attracting the armature to drive the diaphragm for normal vibration, resulting in a hoarse sound or no sound at all. However, if the horn is pressed continuously, a momentary strong current passing through the impedance may still allow it to work temporarily. Moisture due to poor sealing: Although the horn is internally sealed, if the sealing is not tight, moisture or water vapor can enter during car washing or from the surrounding air. This moisture can cause the contact points to become damp, leading to malfunction.