Why does the Dodge Journey's horn sound by itself?
2 Answers
The car horn sounding for no reason may be caused by the power line of the horn being continuously energized. Here are the relevant explanations: There are two factors that can cause the horn's power line to be continuously energized: the steering wheel button getting stuck, remaining in the continuously energized position; the horn relay contacts failing to disconnect normally, staying in contact for a long time. Composition of the horn: The car electric horn produces sound through the vibration of a metal diaphragm. The car electric horn consists of an iron core, magnetic coil, contacts, armature, diaphragm, etc. Operation of the horn: When the driver presses the horn switch, current flows through the contacts to the coil, which generates magnetic force to pull down the armature, forcing the diaphragm to move. The movement of the armature causes the contacts to open, interrupting the current and causing the coil's magnetic force to disappear. The diaphragm, along with the armature, returns to its original position due to its own elasticity and the spring plate, closing the contacts again and completing the circuit. Current flows through the contacts to the coil, generating magnetic force and repeating the above action. This cycle repeats continuously, causing the diaphragm to vibrate and produce sound. The resonance plate is rigidly connected to the diaphragm, making the vibration smooth and the sound more pleasant (i.e., the principle of an electromagnet).
When I encountered a similar issue, I found that the horn sounding on its own could be caused by multiple reasons. The most common is a short circuit in the horn button on the steering wheel, or the button being stuck by something, causing the circuit to remain closed. For example, if you place a heavy object in the car that presses against the steering wheel, the button can easily get stuck. Another common reason is a faulty horn relay, which acts like a switch—if it sticks, it keeps the horn powered continuously. Aging wiring or damaged insulation can also cause a short circuit, especially during the rainy season when moisture seeps into the wiring. If your car has an anti-theft system, false triggering can also make the horn sound. In such cases, I recommend first trying to turn off the engine or disconnect the negative battery terminal for a few minutes and then reconnecting it to see if the issue resolves. For safety, it's best not to attempt repairs on the road—visit a professional repair shop as soon as possible to inspect the specific components. Don’t underestimate this issue to avoid draining the battery.
