Easy Ways to Fix Car Horns, How?

Easy Ways to Fix Car Horns, How? – The horn for most people is a very trivial thing. Not as important as engine oil or coolant radiator, is not it? But are people who ignore the horn also not worried if the horn gets damaged? Does not seem. Almost everyone I meet is nervous when he or she is driving a vehicle without the horn working properly.

Reflecting on the anxiety cases of people who drive cars without a good horn, it is clear that the horn is an important part of the vehicle. Indeed the horn is an important part of a car. This includes how important the horn is on the highway. Telling other people or even animals that we want to pass that way. With the information that we are there, the probability of an accident on the highway occurring is very minimal. Before we go further into the breakdown of car horns, let’s first know the types of car horns.

Types of Car Horns – Easy Ways to Fix Car Horns


There are various types of car horns available in the market. Actually, there are two options to give a warning when you want to overtake the vehicle in front of the vehicle. The first gives a dim light and the second gives the horn. This is so that the vehicle in front of you knows that your car wants to overtake it.

Of the two options, honking the horn is considered more effective than dim lights, especially during the day. The horn itself is a component that must be present in every vehicle, whether a motorbike, car, bus, or train. So, do you know where the horn came from? The sound of the horn comes from a vibration that comes from the components that make up the horn itself. We can distinguish the type of car horn based on the difference in sound.

The sound varies, so it is not uncommon for many people to replace their standard car horn with a horn that has a louder sound. The goal is to make the horn easier for other drivers to hear and make it sound more luxurious. Before you buy a horn, pay attention to these 3 types of horns so you don’t make the wrong choice;

1. Alternating Current (AC) Horn

For this first type, it is actually rare in four-wheeled vehicles. Most of these types of horns are on two-wheeled vehicles. Well, the electric horn itself uses an electric magnet. With this electric magnet, the horn will produce a sound like a horn in general. The trick is in electric magnets there are poles so that later the poles will alternate, from north to south and vice versa.

Easy Ways to Fix Car Horns
Horn 6V 9W Alternating current (AC) 70MM Chrome – Easy Ways to Fix Car Horns.

why that thing could happen? That’s because of changes in the frequency of the electric current or alternating current. This continuous frequency change will produce vibrations in the membrane, the result is sound. A horn with alternating current or an AC horn has several drawbacks, one of which is that it follows the rotation of the engine. That is, if the engine speed drops, the frequency of vibration on the horn will also decrease.

Therefore, this type of horn will depend heavily on engine speed. And the loud and weak sound of the horn will depend on the high and low speed of the engine. In some ways, this is very useful, but it is also a drawback because not all the time the horn can sound as loud as we would like.

2. Direct Current (DC) Horn

Well, next is an electric horn with direct current. This DC horn is a very different type of horn from the AC horn above. On the horn with a direct current, there is no change in the frequency of the current, this is because the current on the DC horn is unidirectional. Various types of car horns have a more solid sound. However, in this horn system, it is necessary to contact a breaker on the membrane so that the horn does not continue to sound.

Easy Ways to Fix Car Horns
Horn 12 Volt Direct Current Big Black – Easy Ways to Fix Car Horns – Easy Ways to Fix Car Horns.

The way it works is when we close the breaker contact, an electric current flows into an electric magnet. Thus, the electric magnet will attract components such as plungers and membranes. When the electric magnet pulls on the plunger, the breaker contacts will open, as a result of which the magnetic force disappears. In this condition, the plunger and membrane will return and the breaker contact will be reconnected. This will happen continuously resulting in vibration and sound. There are two types or two types of this DC horn, namely the dish model and the cochlear model.

3. Air Horn

Well, the latter is commonly used in large vehicles such as buses, trucks, and trains. As the name suggests, this horn utilizes compressed air to produce sound. The compressed air itself can come from an electric compressor or an air brake compressor.

Easy Ways to Fix Car Horns

Universal 17inch Single Trumpet Car Air Horn 12V Compressor 150DB Super Loud Air Hose Car Horn Speaker for Truck – Easy Ways to Fix Car Horns.

This air horn is somewhat unique in how it works because to produce a sound that comes out faster, the compressor must be closer to the horn. Why is that? Because the air horn uses a hose or pipe when the compressor is farther away, the sound of the horn will also take longer.

Many car horns are sold from tens of thousands of rupiah to hundreds of thousands of rupiah. The brands also vary, from the unknown to the well-known ones such as Denso, Bosch, and Hella. So from the various types of car horns, which one do you want to choose?

How Do Car Horns Work?

Of the three types of horns listed above, we will focus on discussing one type, namely the DC horn. Almost all cars use this type of horn. Even some two-wheeled vehicles have also used many types of DC horns. Meanwhile, large vehicles such as buses and trucks, for example, mostly use air horns. However, usually, trucks and buses, have an additional component in the form of an air compressor.

But even though they are different, these three horns have the same function. Namely giving a signal to road users who are in front to notify them that there is another vehicle behind it.

Horn System Circuit with Relay

Cars and motorcycles generally have a similar circuit. The horn circuit with a relay will be safer and more durable if we compare it with a circuit without a relay. This is because the relay can be used to secure the switch and drain current efficiently.

Easy Ways to Fix Car Horns
The basic circuit of a horn consists of an ignition key, battery, horn unit, fuse, and relay – Easy Ways to Fix Car Horns.
In simple terms, the horn will sound when the current from terminal 87 enters the horn component. What is the direction of the current in this circuit?

The direction of electric current in this circuit starts from the battery. Positive electric current flows from the battery and then enters the ignition. If the user turns the ignition to the ON position, the current continues to flow to the horn control circuit. This electric current will enter terminal 85 and exit through terminal 86.

The output of the relay, current will flow directly to the horn switch before it meets the ground. When the switch is activated, the controller circuit will be connected. This relationship will affect the relay horn. Where between terminals 85 and 86 there is a winding that will generate an electromagnetic force if there is an electric current flow. This electromagnetic force will attract the contacts above the coil. So terminals 30 and 87 on the relay will be connected.

On the other hand, current from the battery flows through the fuse horn and goes straight to terminal 30 on the relay horn. Current will come out of terminal 87 and directly connected to the load, in this case, the horn. Since terminals 30 and 87 are connected by winding pull, the current from terminal 30 of the relay will flow to terminal 87 of the relay. This causes the flow of current to the horn.

When the horn switch stops being pressed, the circuit will also be disconnected. So the magnetism in the winding will be lost. The loss of this magnetism will have an impact on the contact being disconnected again. So that terminals 30 and 87 relays are also disconnected. This will cause the horn to go off.

Horn Circuit with Alarm

A series of modern horns, generally include an alarm system as a safety system. So there is a difference in this horn circuit. In simple terms, the modern horn circuit is described as the circuit below.

Easy Ways to Fix Car Horns
The basic circuit of a horn with an alarm module consists of an ignition key, battery, horn unit, fuse, relay, alarm module, and engine control unit (ECU) – Easy Ways to Fix Car Horns.

Either the main current or the horn controller current will be directly connected to the relay. While at the output of terminal 86 there are several components that will regulate the horn control system. Current from terminal 86 does not go directly to the switch or ground but enters the ECU – Engine Control Unit. The ECU as the controller component will receive a signal from the horn switch when activated, and also receive a signal from the Ignition key, which generally has Immobilizer technology.

When these two signals are met, the ECU will connect the current from terminal 86 of the relay to the mass. This will cause the contact between terminals 30 and 87 to be connected to the relay. Until the horn sounds.

On a separate line, there is also a circuit originating from the relay output branch (Terminal 86). The current from terminal 86 of this horn relay will be connected to the car alarm system. So the horn will sound. The sound that has this interval is generated because the alarm module connects the current from the relay output 86 to a period with a certain interval.

However, individual alarm systems that are installed separately generally do not include a horn as a reminder. because this system usually has its own sound actuator which has a distinctive sound.

Car Horn Damage Type

What’s the problem with the car horn? We will find out here. But before that, remember my explanation above. I mentioned that there are three types of horns in general, namely AC horns, DC horns, and air horns. Well, all three have different damage from each other.

For AC horns, the damage is usually in the amount of power that enters the horn circuit. Because this depends on the size of the engine speed, it is clear that the most common problems are related to engine failure. The engine may experience problems such as abnormal idle rpm for example. In this condition, it is clear that the horn looks like it will be damaged. However, damage to the AC horn unit is also very possible.

Meanwhile, for air horns, most problems come from weak air pressure. The damage could come from the air compressor supplying air to the horn system or a leaking hose that delivers compressed air. In addition, damage to the air horn unit is also unavoidable and we must replace it if it has problems.

Well, the DC horn does have special behavior. Because DC horns tend not to depend on other systems such as AC horns or air horns.

On the DC horn there are several problems that often occur, such as the following;

  • The horn does not sound at all – This is a malfunction that occurs due to the disconnection of the power supply from the battery. The problem can vary, but most often it is due to a faulty fuse. However, it is possible that the problem stems from something else. And following the horn’s electrical path is one of the best ways to pinpoint the problem.
  • The horn sometimes sounds sometimes not – This is also often the case. If in the first case because the fuse is broken, then this is different. Most often I encounter this kind of case because the relay is starting to break or the horn switch has carbon crust and we need to clean it.
  • The horn sounds weak – This case is different from the first and second. I often encounter this problem for several reasons. First, usually, the fuse holder burns out the most. Both the presence of a dead fuse and the last are due to a fragile electrical cable.

Easy Ways to Fix Car Horns

As we all know, the damage to the horn includes the horn off, the horn sounding weak, and of course, the horn that sometimes turns on sometimes turns off. There are many ways for people to solve these problems. Some immediately replaced the horn unit, some replaced the relay and fuse, and some immediately dismantled the horn button. Well, that kind of guessing is not good. That’s because we might guess wrong and instead, it will be a new problem related to the presence of other components.

So what’s the best way to fix your car horn? The best way is to carry out inspections in stages. Careful inspection with the right sequence of steps will help us in repairing the horn. The order from the simplest to the most complex we can do. Therefore, it is necessary to have structured steps so that you can easily repair your car horn. Here are the steps you need to take to repair your car horn.

Step 1; Check the fuse box

In this first step, you need to follow the following work order;

  1. Through the owner’s manual, you will know the position of the fuse box. It could be in the cabin or it could be outside. However, it is usually in the fuse box on the hood. Look at the instructions on the fuse box, and find the horn fuse.
  2. If you have found the position of the fuse in the fuse box, please take the beak pliers or the fuse removal tool in the fuse box. Gently remove the fuse from the holder.
  3. After removing the fuse, pay attention to the fuse holder first. If it looks burnt, there may be a short circuit in the line. But if not do a fuse test. If, in fact, the fuse is blown, try replacing it with a new fuse. Remember, replace with the same size fuse as before.
  4. After selecting the fuse with the appropriate size, please install the new fuse. how to install it is also simple, simply by pushing the fuse into the fuse holder slot correctly.

Supposedly, replacing the horn fuse will not affect the rest of the electrical system. But in certain cases, after we replace the fuse, and we ON the ignition, the airbag indicator light will turn on. If you are in doubt about this condition, please take your vehicle to an expert or to a trusted repair shop.

Step 2; Check the Horn Relay

Have you done the first step and it turns out that the car horn is still sounding weakly? Then please continue to step 2. In this second step, you have to check the horn relay. If you don’t know where the horn relay is, please open the owner’s manual. There you will find the location and position of the horn relay.

How to check your car horn relay? The easiest way to check if the relay is working properly is to swap the horn relay with another identical relay. If you have prepared a new horn relay that is even better. But what if you don’t have a new relay ready? Relax, the horn relay design is usually the same as some other relays in a car’s electrical system. Take the relay in the electrical circuit in the fuse box and attach it to the horn relay holder. If your horn sounds fine, then obviously it’s a horn relay problem and you can simply replace it with a new one.

Step 3; Check the Horn

If you have done steps 1 and 2, it turns out that the condition is fine, please continue to step 3. You need to find and open your car horn. You can directly connect one of the horn connectors to the positive battery terminal and the other to the battery negative. If there is a + & – sign on the horn, follow the prompts. Pay attention to whether the horn sounds properly or not. If not, then obviously it’s a problem from the horn.

Remember on a vehicle there is more than one unit of horn. Therefore, to check the condition of the horn you have to check it one by one and all you have to check. If you find one that is damaged, you simply replace it. However, if there is some or all of the damage, then you must replace all the damaged horn units.

Step 4; Check the Horn Switch

Up to the third step, meaning those parts which of course you can do yourself. It’s a bit different in step 4 because the fourth step checks the horn switch. The horn switch is the part that connects the power from the electric current source to the horn unit. If this part is damaged, obviously there will not be electrical power to the horn unit and the horn will turn off. However, the damage can be in the form of interference, for example, the horn switch is full of carbon scale. This results in the sound of the horn sounding weaker than normal.

Whether it’s a broken horn or just a dirty pile of carbon, we have to disassemble the steering wheel to repair the horn switch. The problem is that the horn in modern cars is on the steering wheel which is integrated with the airbag system. We know that airbags inflate very easily and if we’re not careful it’s obvious when we fix the horn switch it will happen. This is the reason why in step 4 I say if you are in doubt you should take it to a repair shop or to an expert.

Step 5; Check Horn System Wiring

If the wiring system is normal there is no reason after you do steps 1-4 the horn is still not normal. That means clearly the problem is in the electrical circuit. For this step, again, if you are neither an expert nor a hobbyist, it will be difficult to do it.

In this step, you at least know about the concept of electric current and voltage. One more thing, you should also understand which is the negative wire and which is the wire for the incoming current from the voltage source. Therefore, if you are in doubt, please take it to a repair shop or to an expert so that a short circuit does not occur which is more severe than before.

How do make a car horn sound louder?

Is there a way to amplify the sound of our car horn? It looks like we have the same volume setting on our audio system. But unfortunately not like that on the horn system. However, we can say that loudening the sound of the horn can be analogized as the horn stays on the sound lever in new conditions. Well, if this is the case there is a way that we can do it on our car horn system.

The first is to adjust the adjusting bolt on the horn unit. It’s on the back of the horn. Some may not exist but most DC horns have a horn adjuster. You can turn the adjusting screw with a screwdriver to get the sound you think is the best.

The second way is to add a relay to the standard circuit of your car horn. Consider the following basic electrical circuit of the horn.
Easy Ways to Fix Car Horns
Basic electrical circuit horn with three relays – Easy Ways to Fix Car Horns. Usually, the manufacturer only installs one relay in the horn electrical circuit. Adding one relay to each horn will add stability to the flow of electric current to the horn. So, please add a relay on every horn in your car to make it even better. This is the reason the horn will sound louder when we add a relay to each horn.

In the picture above, there are 3 horn relays. One relay is the original circuit relay from the automotive manufacturer. Most automotive companies only install one relay for one horn electrical circuit. You can find the relay in the relay box – depending on the type of car, sometimes it is in the cabin and some in the engine trunk.

Meanwhile, the next two relays are additional relays. One relay goes to one horn so each horn gets a supply from each relay. With this addition, the electric current flowing into the horn will be more stable. This also prevents the horn from sounding at all when only one of the relays is faulty. From my experience, installing two additional relays will make the horn sound louder than using only one relay.

Is it enough to add two relays? The answer depends on the number of horns you have on your car. If your car has two horns, it is enough to add two relays. However, if your car has three or more horns, then you should add a number of horns to your car. Simply put, one relay for one horn other than the relay from the manufacturer.

Conclusion – Easy Ways to Fix Car Horns

From this article, we can get some important things. First, cars for general use a DC horn type. Meanwhile, small vehicles such as motorcycles use AC horns. Heavy vehicles such as trucks and buses, use the air horn as a signal. Second, even though the manufacturer has designed it in such a way for the horn series, we can still modify it to get a normal sound from the horn.

Maybe you have a different experience with the horn problem. Please add in the following comments column, to add to the full details of our article above. Thank you.

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