What is the purpose of adding a relay to a car horn?
3 Answers
Horn relay serves to amplify the current. Below is relevant information about horn relays: 1. Introduction to horn relays: When the horn button is pressed, current flows through the circuit to the electromagnetic coil of the horn relay. The electromagnetic coil attracts the moving contact switch of the relay to close, allowing current to flow to the horn. The current activates the electromagnet inside the horn, causing the diaphragm to vibrate and produce sound. 2. Advantages of using horn relays: When a single electric horn is installed in a car, the horn button usually controls it directly. However, most cars are equipped with high and low tone horns, or even high, medium, and low tone electric horns to achieve better and more pleasant sound effects. When two or one electric horn operates simultaneously, the current can reach 15A or even above 20A. If the horn button is used for direct control, the high current will quickly burn out the horn button. Therefore, a horn relay is employed.
I remember installing a horn relay on my old car back in the day, mainly to prevent frequent failures of the original switch. The horn requires substantial current, and when powered directly through the steering wheel button, the switch contacts were prone to burning out or developing poor contact. Over time, the button would become sticky or even fuse. After adding the relay, the switch only handled a small current signal, while the heavy current was managed by the relay. The horn's sound became notably louder and more powerful, and there were no more delays in honking during emergencies. An added benefit was protecting the car's original circuitry, preventing overheating and potential damage, thereby extending the vehicle's overall lifespan. This minor modification is particularly effective for older cars—low cost but with significant results. I recommend experienced friends give it a try.
As an enthusiast who frequently engages in car modifications, adding a relay can really elevate your horn by several notches! It acts as an intermediate switch—when you press the steering wheel, it triggers a low-current signal, and then the relay switches to a high current for the horn, instantly making the sound clearer and louder, unlike the original weak and dull tone. The benefits include protecting the original car switch from high-current damage and reducing the risk of wire aging. I also used a similar method when adding extra light groups, making the entire circuit more stable and reliable. DIY is simple—just buy a small relay, connect the wires, and you're done in half an hour, boosting your confidence while driving. Whether in city driving or off-road warning scenarios, the response is fast and effective, making it a top-tier modification.
