The horn is one of the important but most underrated components in a car. If your car horn is not working, you will have to use the brakes more often. If it starts honking on its own and doesn’t stop, the problem is even worse because car horns typically have a minimum sound level of 93 dB, and anything above 85 dB can cause prolonged exposure to permanent hearing loss.
How to Fix All Car Horn Problems? The good news is that, unlike many other car problems, repairing a faulty horn is an easy task. Diagnosing a horn is easier than other car noises, and fixing it is less effort than eliminating the whine made by the car.
Car Horn Repair Guide: How Does a Car Horn Work?
Car horns work on the same principle as speakers. When you press the horn button, it completes the circuit and the current is converted into sound. The minimum sound level allowed for car horns in the United States is 87dB.
If you need to replace your horn because it stopped working, or you need a better one, it’s important to make sure that the speaker you get is within the legal limits for sound levels.
Things that make the horn work include:
- The button to complete the circuit
- A horn relay that sends current to the horn
- Power supply, battery
- The horn itself
Types of Car Horn Problems
The problem with car horns can be divided into three different types:
- The horn stops working
- It makes a faint sound
- It starts honking on its own and won’t stop
How do you fix a car horn that makes a faint sound?
How to Fix All Car Horn Problems? Most cars have more than one horn that collectively produces a horn sound. If one of them fails, the system won’t be able to make the right sound.
However, before replacing the horn, make sure that your car’s battery is not faulty. You can use a voltmeter to check the battery. The battery voltage should be above 12 volts.
To diagnose which horn is problematic, follow these steps:
- Open the hood of your car.
- Find the horn in the engine compartment; It is usually located close to the radiator.
- Ask someone to honk their horn.
- Place your hands on the horn.
- Those that do not vibrate when the horn sounds are faulty.
Before replacing the horn, make sure that both wires are connected to the horn and that the wires are not damaged. If the wire is connected correctly, it means that the horn is faulty and you need to replace it.
To replace your car horn, follow these steps:
- Unscrew the horn from the car and disconnect the electrical connection.
- Buy a replacement horn from your local auto parts store.
- Screw the new horn into place and connect the wires.
Car Horn Repair Guide: What to Do If Car Horn Doesn’t Work at All?
If the horn stops working completely, the problem may be one of the following:
- Horn fuse
- Horn relays
- The horn itself
If this is the case, the solution is mainly to replace the car horn.
How can you tell if a fuse is faulty?
As with any other electrical problem in a car, you need to start diagnosing with the fuse. Follow these steps:
- Locate the fuse box in your car.
- Read the fuse diagram to locate the horn fuse.
- Remove the fuse and check it.
- If the electrical connection inside the fuse is blown out, the fuse is faulty and you need to replace it.
- If there is no problem with the fuse, you need to check the other components.
How can you tell if a relay in a car is faulty?
The function of the horn relay is to turn on the horn when the horn button is pressed in the car. It allows the switching circuit to run at a low current, while the horn operates at a high current. By doing so, the switching circuits use low-spec wires and prevent them from heating up.
If the fuse works and the horn doesn’t make any sound at all, the relay is most likely the source of the problem.
To diagnose a relay, follow these steps:
- Locate the relay and fuse box in the engine compartment and use the circuit diagram on the fuse box cover to locate the relay that controls the horn.
- Place your finger on the relay and ask someone to honk their horn in the car.
- If the relay clicks when the horn sounds, it is working. If it doesn’t make any sound, the relay is broken.
If both the relay and the fuse are working, the problem is with the horn itself. You can replace it in the same way we did in the previous section.
Car Horn Repair Guide: How to Repair a Car Horn That Won’t Stop?
If your car horn honks on its own even when the button is not pressed, the problem may be due to one of the following reasons:
- The horn button is faulty.
- Horn relay failure.
- There is a short circuit in the wiring of the horn.
To solve these problems, you need to diagnose exactly what the problem is. Here’s how you can do it:
- Find the fuse box in the car, remove the cover, and look at the circuit diagram to find the horn fuse.
- If the fuse is removed and the horn stops, it means that the horn button inside the steering wheel is broken.
- Replace the horn button with a new one, this will solve the problem.
If removing the fuse does not stop the horn, the problem is most likely with the horn relay. To fix it:
- Open the engine compartment and locate the fuse/relay box.
- Open the relay box and find the horn relay. Removing the relay will stop the horn.
- Swap the relay with another relay in the box, as there are many of them, usually the same.
- Ask someone to honk the horn in the car, if the horn is working, you just need a new relay.
If replacing the relay does not solve the problem, it is a short circuit in the horn wiring. You can check it with an electrical continuity tester. However, these issues are often complex, and it is best to seek professional help.
Disclaimer: If you have limited knowledge of cars, consult a mechanic instead of trying to fix the problem on your own.
Frequently Asked Questions:
How to Fix All Car Horn Problems? How do I replace my car horn?
Locate the horn, unscrew it from the car, disconnect the electrical connector and replace it with a new one. Make sure the sound output of the speakers you use is within the legal limits allowed in your area.
Can a car horn be repaired?
If the problem is with the power supply of the horn, the car horn can be repaired. If the horn itself is broken and there is no way to fix the problem, you need to replace it with a new one. Car horns are disposable and generally cannot be opened and fixed.
Why does my horn honk on its own?
If the horn honks on its own, it may be due to a broken relay, a short circuit in the horn power supply, or a broken horn button.
Car Horn Repair Guide: How to Check if the Horn Relay Is Broken?
Locate the horn relay and swap it with another similar relay in the relay/fuse box. If this solves the problem, the relay is broken. Another way to tell if a horn is bad is to put your finger on the relay and ask someone to honk it. If the relay clicks, that’s fine. If it’s silent, it’s not good.
How do I attach a car horn to a button?
To connect a car horn to a button, connect the negative pole of the horn to the car body and the positive pole to the button. Provide the positive terminal for the button, and the horn will work with the button.v
