car horn not working How to replacement

car horn not working How to replacement

What is a horn?

A horn is a device that emits a horn. In the Road Traffic Act, it is called a “horn” and the usage scene is defined. The main places of use are intersections with poor visibility and roads with a “horn” sign. It is against the law to sound the horn in any place other than these (except when sounding to prevent danger).

The English word for horn is Horn. Klaxon is a word that the company name “Klaxon” sang, and does not refer to a general horn.

How to choose a horn | Choose a product that meets safety standards

The volume of the horn

When purchasing a horn, be sure to check the volume. The Road Transport Vehicle Law stipulates the volume standard for horns as follows.

The volume was measured twice at a position 7m ahead of the front end of the car, and the average value was 87 to 112dB

The volume was measured twice at a position 2m in front of the front end of the car and 1m above the ground, and the average value was 90 to 115dB
dB (decibel) is a unit that expresses the sound pressure level. If multiple horns produce sound in conjunction with each other, the total sound pressure must fall within the above criteria. When choosing a horn, check the sound pressure level of the product.

The tone of the horn and how it sounds

When choosing a horn, pay attention to the tone and the way the sound comes out. The Road Transport Vehicle Law stipulates that the standard for the sound of a horn is “the sound of the alarm sound generator is continuous, and the volume and tone are constant.”

A horn that automatically interrupts the emitted sound and a horn that automatically changes the volume and tone do not meet the safety standards. A horn that can change the volume and tone in the driver’s seat is also NG.

From the above points, a music horn (a horn that plays a melody) is not recognized as a horn. Bells and sirens are also incompatible. In addition, the horn changeover switch is also illegal depending on the installation location. When using the changeover switch, install it in a place that cannot be operated from the driver’s seat.

Many horns can be installed regardless of vehicle type or manufacturer

The horn is a versatile part. Many products can be installed on most vehicles regardless of vehicle type or manufacturer.

However, be careful of cars with a narrow mounting location (mainly behind the grill). There may not be enough space to install an external horn. Especially for light cars, the space for installing the horn is narrow. Please choose the horn paying attention to the size.

Gorgeous sound is a “swirl” horn

The main types of horns are “flat” and “swirl”. If you want a gorgeous sounding horn, choose the swirl type. The spiral horn has a trumpet-like resonance part, and this part produces a unique sound that resonates with “Fern”.

Flat horns (most of the genuine products are of this type) have different structures, so they do not produce the same sound.

Wiring knowledge is required to replace the horn and horn

You can replace the horn by yourself. However, wiring knowledge is essential. It is necessary to prepare wiring materials and relays (automatic switches) that match the new horn and connect them properly.

Of particular note is the replacement of a flat horn with a spiral horn. If the wiring is incorrect, the original sound quality of the product may not be obtained, or the fuse may blow when the horn is sounded.

If you are worried about wiring by yourself, ask a professional to replace the horn.

Horn that does not sound how to fix if it does not work

What to do if the horn does not sound: the most frequent causes and how to solve when the car horn stops working

The car horn not sounding is a recurring problem on cars of all ages. Since this is an acoustic warning device to be used in case of danger, if the horn does not work, you risk not passing the car inspection. Although excessive use has made the horn a tool to greet, celebrate, express anger, etc., when the horn does not work, you run serious risks when driving


If the horn does not work when you press the button on the steering wheel, it does not necessarily mean that the “horns” or the emitter mounted in the engine compartment are broken and need to be replaced. There are many reasons why the car horn stops working, including wear, damage or environmental factors. Among the main causes of a horn that does not sound, to be explored if you want to try the DIY route, there are:

  • Damage to the horn (usually located on the rear of the bumper, on the cross member in the radiator area). Likely on cheaply repaired used cars after an accident that the new owner is unaware of;
  • Damage to electrical wiring or power outage in the horn circuit. The causes can be varied, from wires gnawed by mice to oxidation on the contacts, from the blown fuse to the damaged button on the steering wheel. By the way, pressing the horn hard in traffic won’t make it sound louder, but it risks crumbling the spring system under the airbag. Remember it! Before we move on to tips on what to do with a horn that doesn’t work, we want to remind you not to improvise. So, follow the advice on how to fix it until you are aware of your abilities, besides it is better to leave it to an experienced car repairer. The reason is simple: removing and testing the horn button on the steering wheel certainly also requires removing the airbag. In this case, it is better to stop at the less risky controls on the day.


If the horn does not work, because it simply does not sound from the driver’s seat, it does not mean that it is broken. The first thing to do is to identify the cause, which as mentioned can be electrical (there is no power supply to the “horns”) or mechanical which we will see later. The most immediate and foolproof thing to do is to check if the horn fuse is blown or intact. To do this, check the position of the low-power fuse control unit in the car manual, locate the horn fuse, extract it, check it and replace it with an identical one (if blown) or put it back in its place


From this point on, it may be necessary to get your hands dirty or simply go to the workshop to repair the non-working horn. If the horn fuse is not the cause of the problem, then look for the fault elsewhere by reversing the circuit from the horn to the steering wheel:

  • Check if pressing the button the horn does not sound but croaks faintly. In this case it is likely that water has entered the trumpet. It might be enough to take it apart and let it dry;
  • If the horn does not sound, check whether the correct voltage (> 12V) is detected by pressing the button on the horn’s electrical connections with a multimeter. You can also take the opportunity to spray contact sprays and eliminate any non-visible oxidations;
  • If checking the cables, you do not notice burns, interruptions or cuts, and pressing the horn does not reach the horn but the fuse is intact, all that remains is to check the operation of the button (broken or oxidized). If the car is not equipped with an airbag, simply detach the button, disconnect the two cables below and check if by connecting the multimeter (in resistance measurement), the display shows that there is continuity when the button is pressed. In all other cases (horn not visible from above or below in the engine compartment, presence of airbags on the steering wheel, etc.) it will be faster and safer to repair or replace the non-functioning horn by an expert.