Why Does the Car Horn Sound Change?
3 Answers
During rainy weather, it is easy for the horn to get wet from rainwater, leading to damage. When the horn does not sound, common fault locations are usually the horn itself, the horn switch contacts, or the horn wiring harness. The reasons for a change in horn sound are as follows: 1. Horn switch contacts: Sometimes, the horn switch does not activate. If the horn sometimes works and sometimes doesn’t, most of the time, the contacts inside the horn switch are not making good contact, and sometimes the issue lies with the horn itself. 2. Poor plug connection: A hoarse or distorted sound is mainly caused by poor plug connections, especially around the steering wheel where various contacts are frequently used and prone to wear. 3. Check the fuse: First, check if the fuse is blown. Then, unplug the horn and use a multimeter to measure whether there is power when the horn switch is pressed. If there is no power, inspect the horn wiring harness and relay; if there is power, the issue is with the horn itself.
I recently encountered an issue with my horn changing its sound, and later discovered it was caused by oxidation of the internal contacts. Normally, water vapor from car washing seeps into the horn chamber, and over time, the metal contacts become poor, resulting in a hoarse sound. In some older cars, rusted or deformed spring plates can also cause the horn to go out of tune. Last time, I saw a neighbor's car horn got water inside, making a sound like a duck's quack, which was particularly funny. If you encounter this situation, don't press the horn forcefully. First, check the horn's mounting position for any water stains and try drying it with an air gun. If the sound still isn't right, you'll need to open it up and clean the contacts. If you're not handy with such tasks, it's safer to take it to a repair shop.
A distorted horn sound is most likely an electrical circuit issue. Voltage fluctuations can cause abnormal vibrations in the horn coil, making the sound waver like a throat clearing. Last week, after installing fog lights on my car, the horn started sounding off-key—turned out to be caused by poor grounding. Modified vehicles require extra attention, as improperly connected wiring can interfere with the horn's power supply. Use a multimeter to check the horn voltage; it should normally fluctuate around 12V with no more than a 0.5V variation. Burnt relay contacts can also lead to unstable current, resulting in a hoarse, noisy sound. DIY fixes for such faults carry risks; it's recommended to consult a professional auto electrician for diagnosis.
