How to Connect a Car Horn Relay?
3 Answers
Disconnect the non-ground wire from the horn and connect it to the terminal labeled 'button' on the relay, leaving the horn ground wire untouched. Then, connect the terminal labeled 'battery' on the relay to the positive terminal of the battery using one wire, and use another wire to connect the other terminal on the horn. Finally, ground the relay housing. Below is an introduction to the relay and electric horn: 1. Relay: A relay is an electrical control device, commonly used in automated control circuits, where it serves functions such as automatic regulation, safety protection, and circuit switching. 2. Electric Horn: A car electric horn produces sound through the vibration of a metal diaphragm. It consists of components such as an iron core, magnetic coil, contacts, armature, and diaphragm.
I once helped a friend repair a car in the garage. Installing a horn relay mainly makes the horn work more smoothly and reduces the burden on the original switch. The operation is quite simple: first, disconnect the negative terminal of the battery to ensure safety. Then locate the original horn switch wire and connect it to the control terminals of the relay, usually pins 85 and 86. Connect the main power line to pin 30, and the output terminal pin 87 to the positive terminal of the horn. Finally, don’t forget to connect the ground wire to the car body or ground terminal. The whole process can be done with basic tools like pliers and electrical tape to avoid exposed wires causing a short circuit. After completion, reconnect the battery and test it—the horn should sound much louder. This method is suitable for most car models, and the key is to proceed step by step patiently without rushing to power it on. Remember to regularly check the connection points for oxidation, as prevention can save a lot of trouble.
I've been driving for years, and connecting a horn relay is a piece of cake for me. The key is to protect the original switch: you pull out the original horn's switch wire and connect it to terminals 85 and 86 of the relay; the main power positive (taken directly from the battery or relay box) connects to terminal 30, and the output terminal 87 connects to the horn's positive. Make sure the ground wire is securely fastened. Always disconnect the battery fuse before starting—safety first. All you need are a screwdriver and some tape, nothing complicated. I've helped neighbors with this before, took about ten minutes, and the horn sound even improved. If the wiring is old, replace it sooner rather than later to avoid damaging other components later. Remember, when testing after wiring, just honk twice—keeping it on for too long isn't good for the relay. This kind of job is perfect for car owners to do themselves—saves money and teaches a skill.