What Causes the Horn to Keep Sounding Nonstop?
3 Answers
When a car horn keeps sounding continuously, it is generally due to the horn button on the steering wheel being stuck in the pressed position, keeping the circuit constantly energized. Another common cause is the relay contacts becoming welded together and failing to disconnect properly, resulting in continuous contact. Additionally, a short circuit in the horn's negative switch wire grounding can also cause this issue. Below is expanded information: While driving: Avoid prolonged horn usage. Also, when pressing the horn button, do not apply excessive force or brute strength, as this is how most horns get damaged. During car washes or rainy days: Take measures to prevent the horn from getting soaked with large amounts of water. If water ingress is discovered, promptly dry it off. About relay contacts: Relay contacts exist in either normally open (NO) or normally closed (NC) states, which can be simply understood as switch contacts that connect or disconnect signals. The performance of contacts is influenced by factors such as contact material, contact pressure, load type, operating frequency, atmospheric environment, contact configuration, and bounce characteristics.
Yesterday I encountered the embarrassing situation of my car horn continuously honking while driving, so let's discuss the possible causes. The most common reason is the horn button on the steering wheel getting stuck. Some car models have buttons designed under the airbag cover which can easily get stuck, especially if a steering wheel cover has been used or if drinks have been spilled. Another possibility is an issue with the clock spring component inside the steering wheel. That part is responsible for the electrical connection when the steering wheel rotates, and if it fails, it can cause a short circuit making the horn honk randomly. There's also the chance of the relay sticking together. My friend's old car had the horn honking all night because of this. Lastly, check the horn itself, as aging wiring harnesses grounding and short-circuiting can also cause this. It's recommended to disconnect the negative terminal of the battery as an emergency measure to avoid draining the battery and complaints from neighbors, then promptly seek a professional mechanic for inspection.
I've seen the horn honking non-stop issue many times, and generally it can be divided into several problem areas. The button switch getting stuck accounts for 60-70% of cases, especially after rain when water ingress causes oxidation and makes it harder to reset. Wiring system issues are also common, such as damage to the clock spring assembly in the steering wheel or accidental contact with wiring harnesses during audio system modifications leading to short circuits. Relay failures are frequent too - you can temporarily solve this by locating and removing the horn relay in the fuse box. Don't overlook quality issues with the horn itself or chassis wiring abrasion causing grounding. Remember two key points when handling: first disconnect the battery to avoid blowing fuses, and be cautious of airbag wiring during inspection. While it may seem simple, this issue involves multiple systems, so it's best to have a repair shop use a multimeter to check for continuity break points.
