What Causes a Car Horn to Suddenly Stop Working on Rainy Days?
2 Answers
The reasons why a car horn suddenly stops working on rainy days are as follows: 1. Contact Erosion: Prolonged use of the horn can cause the contacts to erode, creating resistance. This reduces the current flowing through the electromagnetic coil, weakening the electromagnetic 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, a momentary strong current can still pass through the resistance, allowing it to work intermittently. 2. Poor Sealing Leading to Moisture: Although the horn is internally sealed, if the sealing is not tight, moisture or water vapor from the air can enter during car washing, causing the contacts to become damp and malfunction. 3. Poor Contact at Electromagnetic Coil Terminals: Some horns have aluminum rivet connections for the enameled wire terminals of the internal electromagnetic coils instead of secure soldering. If the insulation varnish on the wire ends is not properly removed or the rivet connections are loose, poor contact can occur, leading to horn malfunction. This type of fault is due to the horn's quality and cannot be repaired; only replacement with a new part is possible.
I've seen this happen a lot - the horn suddenly stops working when driving in the rain. It's mainly caused by water seeping into the electrical system and causing a short circuit. On rainy days, the high humidity allows moisture to easily invade the horn's wiring connections or relay box, leading to poor contact or blown fuses. My previous car had a similar issue: pressing the horn produced no sound, but I could feel slight vibration in the steering wheel, indicating the button signal was being sent but there was a problem with subsequent components. Upon inspection, it turned out the relay contacts were corroded by rainwater, preventing signal transmission. Fuses are also prone to tripping in humid conditions. Before driving in the rain, I make it a habit to check the horn's responsiveness - if it feels less sensitive, I address it beforehand. Additionally, I choose dry parking spots to minimize moisture accumulation. If the horn fails while driving, don't panic - use flashing headlights as an alternative signal, safety comes first. During repairs, have the technician check the entire wiring's sealing - sometimes simply cleaning the contacts solves the problem.
