What causes a car horn to sometimes work and sometimes not?
2 Answers
Reasons why a car horn sometimes works and sometimes doesn't: 1. Burned contacts on the horn due to prolonged pressing. This weakens the current through the electromagnetic coil, reducing electromagnetic attraction and preventing the armature from properly vibrating the diaphragm, resulting in a hoarse sound or no sound at all. 2. Poor insulation treatment of the enameled wire on the electromagnetic coil terminals or loose rivet crimping can easily cause intermittent connection faults, leading to poor horn performance. 3. Inside the horn, if the seal is not tight, moisture may enter during car washing or water vapor may be present in the internal air space, which can easily cause the contacts to become damp and fail to function properly.
Last time my car horn had the same issue, sometimes working and sometimes not, which was really frustrating. I thought the horn was broken, but later found out it was due to oxidized contacts on the steering wheel button causing poor connection. I tried fixing it myself: opened the button casing, cleaned the contacts with alcohol, and tightened the wire connectors, which solved the problem. If cleaning the contacts doesn't help, it might be loose wiring, especially the connections under the dashboard that can get loose from vibrations. Also, humid weather can worsen this situation by corroding the contacts. I recommend starting with the button to save the cost and hassle of replacing parts. If you're unsure, it's better to go to a repair shop—after all, driving safety is important to avoid accidents if the horn fails at a critical moment.
