Why do car fuses blow? Why does a fuse blow in a car? Fuses of modern cars, why are they different colors

When a fuse blows in a car, none of the car owners, as a rule, “bother” about it, so what? We'll install a new one... In principle, this is how it is, the fuse already by its name suggests that it protects something from something. By burning, the fuse protects expensive automotive equipment from failure and damage.

But if you look at the root of the problem and “dig” deeper, then the question of why the fuse is on will turn out to be much more serious than it seems.

Why does the fuse blow? This occurs from a voltage overload in the vehicle's on-board electrical network, due to a short circuit of wires, some device, moisture and other sources that can cause an overload.

A fuse that has a band at the points of contact with the terminals with which it is in contact will sometimes leak current, or there may not be any current at all, since in such cases the contact is very poor, or there is none at all. In such cases, a completely “intact” fuse with an intact strip, at first glance, will be inoperative, because no current will flow through the strip.

Current:

If after replacing the fuse you immediately get a blown fuse again, do the following. One by one, turn off all consumers for which this fuse is responsible. Then, to check, touch the tips of the fuse mounting terminals with a screwdriver; when you see sparking, continue disconnecting, and after each new disconnection, check the sparking. By disabling a consumer that is having problems, you will return to working condition circuit protection, after which the fuse will no longer blow. Provided that you repair the faulty device that caused the short circuit and burnout.

Many people install so-called “bugs”, a wire that does not burn out, or install a coin instead of a fuse. This solves the problem of a blown fuse, but does not solve the issue of preventing damage to an expensive device and the circuit itself from high voltage. In addition, this is fraught with fire and melting of the wiring and insulation; as a result, instead of a blown fuse, you will get huge problems and, most likely, a non-working car.

It happens that during a long trip the fuse burns, but there is no spare at hand and nowhere to buy it. In this case, cigarette foil or chocolate foil will help you out, or use a thin wire. This will allow you to reach the nearest auto shop or bus station, at the first opportunity, replace the “home-made bug” with a high-quality fuse of the required rating and continue your movement.

The electrical part of the car includes fuses, which are designed to protect the electrical circuit in the event of any breakdown. How do they look? Every driver has seen the fuse box, and most car owners periodically face the need to replace these elements. But there are often other situations when the fuse is not just blown, but such a disaster occurs regularly. It is not good. Let's try to understand the reasons and find out how to correct the situation.

The main reasons for fuses failure

Among the basic reasons, several can be identified. Some of them are very serious, others are quite simple and banal. For example, a typical situation is when a fuse installed in a circuit fails side lights. As soon as the driver turns on these lights, they immediately go out. And the reason is in this case completely simple and absurd - he burned out because he had less power. Let's try to highlight the main reasons why these elements fail and ruin the lives of car owners.

Bad connection

When the safety element of the car's electrical circuit is poorly connected to the block, if the contacts of the element are not sufficiently fixed, then there is a high chance that plastic parts fuses will melt. Such an element will definitely fail.

In order to solve this problem, experts recommend purchasing a product from another company, which is better known as a manufacturer of components for automotive electrical systems.

But replacing an element with a better and more expensive one does not always solve the problem. Sparks may occur due to oxidized burnt contacts. This contributes to the failure of the fuse. And it doesn’t matter what quality installed element what power does it have? Sometimes you need to first clean the contacts and improve the connection, and then install a new fuse.

Wear

Many people think that fusible elements burn out instantly and immediately. This is a popular misconception - in fact, everything is a little different. IN critical situation when really in on-board network If there is increased voltage, the part will burn out immediately. However, when in electrical network all parameters are within normal limits or exceed the norm only slightly, the fuse part of the fuse may burn out little by little.

The cross-section decreases every time even with minor overloads. At one point, the part will completely collapse. That's why the fuse blows - you don't have to completely disassemble the whole car. The reasons may be quite simple.

Incorrect choice

And this is also a simple reason, but it also leads to unpleasant situations. Often salespeople in stores do not know what they are selling well enough. Also, not every car owner knows the laws under which they operate. electrical circuits. A situation often occurs when the fuse is incorrectly selected for the current in the network. As a result, it cannot withstand the load in the circuit in which it was included. Once the current is applied, the fuse will blow.

Power surges

Voltage surges may occur in the on-board network of vehicles in which safety elements operate.

Due to these surges, fuses can also fail. This can be observed when the electric motor, on which the elements of the electrical on-board network depend, is blocked.

Violation of the scheme

If a fuse has blown, it is worth looking for errors and irregularities in the supply of current to the circuit. When electricity flows through a smaller circuit than the manufacturer intended, the resistance drops. So, more current will pass through the element, and not the one for which it is designed. Most automotive electrical systems are not designed to high loads. That’s why fuses are used there, which will save electronic devices in case of critical situations.

Short circuits

This is one of serious reasons. If opposite polarities come into contact in any way, a short circuit will occur. For this reason, the stove fuse often blows. And it will burn until the owner replaces or insulates the damaged wires.

Short circuits can happen anywhere electrical system car. Many people complain that the fuse that protects the cigarette lighter fails. The first thing you should do is not disassemble the connector, take it out and go for a new one. Everything could be much simpler.

If the cigarette lighter, then the problem may be high power device that is connected to this cigarette lighter. It may also be a matter of the quality of contacts. Often, the adapters are Chinese, and the quality of the contacts in them is very low. Recommended before use radical measures First, carefully examine the design of the cigarette lighter and find weakness. Usually there are such places - a short circuit can easily occur in them. It is necessary to carefully inspect the contacts and, if possible, somehow insulate them. Usually, after the weak point is found and the cause of the short circuit is solved, the cigarette lighter fuse no longer blows.

Diagnostics

The cost of fuses is very affordable. Most people carry them with them - there is a whole set in the trunk. They can be easily installed into the block if necessary. The situation when a fuse fails is quite normal, since even the most reliable chain not protected from voltage and current surges. If these burnouts happen very often, then a thorough diagnosis is needed.

If any of the fuses burns as soon as they are installed in the circuit, then the first step is to find out which device is causing this. To do this, it’s worth looking into technical documentation on the car to find out which devices are in the circuit with this fuse. Then all consumers that interact with this element are included.

Next, take a screwdriver with a well-insulated handle and touch its metal part to the terminals into which the element is installed. If there is a spark, then there is a fault in the circuit. They turn off one of the electrical appliances and touch the terminal again. When the spark does not jump, it will become clear why the fuse blew. The last disconnected device is to blame.

on the road?

If the problem happened while driving, and there is no spare fuse, then the situation can still be solved using improvised means. Instead of safety element You can use a piece of foil from a pack of cigarettes.

This is paper based foil. It is so thin that in the event of a short circuit it will burn out in the same way as a VAZ fuse blows. This will not only improve the operation of the on-board network, but will also protect the circuit from overloads. Some people use wire, but it doesn't provide as much protection. Coins, paper clips, and other metal inserts will remain intact in the event of a critical situation. But the device, which is protected by a fuse, will fail. There is a second option, but it will require minimal knowledge of car electrics. So, if any important fuse has burned out, you can take the protective element of the cigarette lighter and install it in place of the burnt one.

How to buy a quality fuse?

These components for cars cost much less than the electrical equipment they are supposed to protect. Therefore, experts do not recommend saving on their purchase. It is better not to give preference to inexpensive, dubious models. You need to purchase only those products where all parameters are perfectly met.

Since it is not possible to check each of the elements from unknown brands, when purchasing a similar product it is better to pay attention to the products of the companies that produce them. Among the most famous manufacturers. Reviews note "Bosch", "Hella", "Vibe" and "Sound Quest". When purchasing products from an unknown company, you should first check them and only then install them on the machine. You can simply check - new element connected to the battery. If it burns out immediately, then the product is of high quality. If during a short circuit the product does not burn out, but melts, then it is better not to install it on the machine - it will not be able to protect electrical appliances in the event of increased current.

How to replace?

Replacing a burnt out element is quite simple. To do this, you do not need to have specialized tools and knowledge. First you need to find the location of this element. Where could he be? And the fuses are located in different places. In some cars they are under the hood, in others - in the area of the front dashboard. They are hidden under the lid. After opening it, you can remove the burnt element with two fingers and install a new one in the same way.

Conclusion

These are all the main reasons. A fuse blows, which means you need to look for a problem. It can be either simple and banal, or complex, and it will not be easy to find it. It is best to have new protective elements in stock. Then you won't have to hiccup through foil, candy wrappers or paper clips. You can notice the fuse and move on.

» Why do fuses blow in your car?

Diagnosing fuses and why they blow in your car.

Every circuit in a car's electrical system has a fuse that blows and protects the car's expensive wiring. The fuse serves to protect against:

short circuit,
current overload.
failure of automotive equipment

Its cost is low, which is why they are used as protection.

First of all, in the event of a short circuit, it is destroyed fuse link, thereby breaking the wiring chain. Buying and replacing an insert is not difficult or expensive.

Any fuse designed for a certain value of current flow. Only when this value is exceeded does it burn out. Sometimes the manufacturer installs several fuses depending on the power and number of electrical devices in the machine. When a current flows greater than the rated value, the fuse-link melts, i.e. the fuse trips. Now it needs to be replaced with a new one with the same nominal value.

If you install, for example, instead of 10 A, 16 A, then during an overload the fuse can withstand the excess current, but the wiring cannot. As a result, the fuse link will remain intact, and the wires and device must be replaced. If the fuse is set to 8 A instead of 10 A, then the reliability will increase, but if a current flows, for example, 9 A, it will collapse, although with the previous analogue the circuit would have withstood the overload. Car manufacturers also take into account the power reserve on the electrical circuit.

Exist several driver mistakes when using electrical equipment and fuses. For example, instead of a fusible insert they put:

a piece of wire
coins,
nail,
other metal objects

This does not ensure reliable protection. After all, such objects can withstand very high currents, which can lead to overheating electrical wiring and what's worse to .

You should also, after detecting a tripped fuse, find out what is causing the overload in the electrical circuit. It may be that there is a problem with the lights or generator. If the replaced insert burns out again, it is necessary to call back the electrical circuit and look for a short circuit in the wiring or vehicle equipment.

On the consumer market there are a lot of low-quality devices that are inserted into the cigarette lighter and cause the fuse responsible for the operation of the cigarette lighter to blow.

Non-standard vehicle equipment and overload electrical circuits It can also cause blown fuses.

Identifying a faulty fuse

Cars come with one block and two fuse blocks, usually one is located in engine compartment, and the second is under the dashboard to the right of the driver.

The block located in the engine compartment is responsible for equipment related to the direct operation of the engine and everything that works together with it, as well as for external lighting.

As you might guess, the fuse box located in the cabin is responsible for all equipment located in the cabin, including dashboard and lighting.

Often, on the covers of these blocks there is an explanation of which vehicle equipment a certain fuse belongs to. It is also possible to determine at random by examining each fuse for its malfunction; in this case, the main thing is to determine in which block it is located.

Fuse repair

What to do if the fuse has failed during the journey? There is no spare one. There is a way out in this situation if you have a thin copper wire. But here it is important to choose the right diameter of the thin wire depending on the nominal value. This piece of wire should be inserted into the tips of the fuse and pressed well with pliers. Please note that you do this at your own peril and risk!

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It's stupid to underestimate vital role in the vehicle system, elements such as fuses. After all, they are able to protect the electrical component of the car from problems and various types of malfunctions. Most car enthusiasts have most likely encountered them more than once. But we must not lose sight of the fact that if they “burn” too often, this is fraught with more serious problems. Therefore, if you notice that you have to visit car dealerships quite often to purchase such parts, we strongly recommend that you look into this problem in more detail. Therefore, later in the article we will try to reveal the full answer to the question of why the fuse blew.

In the photo - Mazda Demio fuses

Reasons for failure

Remember that each fuse is responsible for a specific “circuit” and overlooking such problems in the first place is fraught with possible future problems in a global sense. A fuse has blown, which means there has been a breakdown in some network, perhaps some device is faulty, or there has simply been a power surge. You can determine exactly what each controller is responsible for using the “manual” for your model or asking on the forums dedicated to the model of your car. I would like to give a list of problems, more precisely the reasons, which could cause the fuses to fail:

Sometimes a situation arises that the fuse simply has an unreliable connection in the “block” (seat), which can lead to melting of parts or simply failure.

To protect yourself, it is better to purchase high-quality components from well-known brands.

Trivial wear and tear. It is mistakenly believed that a fuse can fail instantly after a short-term slight increase in voltage in the network. This is not the case, if the differences are only slightly higher than the norm, it will gradually begin to melt as a precaution, but not instantly. The so-called fusible part in this case gradually burns out until the cross-section finally decreases. Therefore, when buying a new set of fuses, at first it is better to monitor them and check their functionality.

Initially, an unsuitable element was chosen, for example, with a reduced current. If the selected current is less than in the network, it simply will not be able to transfer the load and in this case it will burn out instantly.

It can also fail due to sudden surges in voltage, as already mentioned, for example, due to sudden blocking of electric motors.

Repair methods

As you understand, if you have to change fuses quite often, it means that the problem requires resolution. Most drivers do not worry about the failure of controllers, but simply carry a certain supply of parts in the car that can be replaced at any time. But, if you notice that they burn out quite often, you definitely need to look for the reason and then think about it possible options repair.

Remember, if the fuse lights up immediately after installation, it means that the problem is hidden in which device and it must be “calculated”. There are not so many ways to do this. Let's give the most effective one. So, if some element has burned out, the first thing we do is study the documentation for the model. It is necessary to determine which circuit the blown fuse is connected to, and what devices and devices are connected there. For example, if a fuse has blown on a VAZ 2114, 2110, remember that there are twenty fuses, each of them has its own consumer group. For example, the most common fuses that fail are F1, F9 and F19.

Group F1 includes license plate lighting, instrument lighting, trunk lighting, and dimensions.

Washers are included in group F9 windshield, headlights, as well as heated windshield and rear windows.

For group F19, the brake light relay, dimensions, turn indicators, generator winding, instrument display unit, clock, on-board computer, as well as central locking.

Having determined the “package” of devices connected to the system, we turn on all the devices that interact with this controller.

Get a screwdriver with a closed handle, preferably a special insulated one. Use the metal edge to gently touch the terminals. seat for the fuse. If even a small spark jumps when touched, then the fault is still in the network. To “figure out” what exactly is “sick”, it is necessary to gradually remove the consumers, checking in the same way, touching the terminals. If, after removing the consumer, the spark disappears when touched, then the culprit has been found. We have identified a problematic element, we take it to the technician and determine whether it can be repaired; if not, we buy a new one.

Replacing the fuse

After replacing the source of the fault, you can safely buy a set of fuses that suit you. And here attention needs to be focused on which controller was there initially. If we threw it away and forgot, we turn again to the “manual” for the car.

The photo shows the fuse diagram of the Opel Astra J

Remember that all fuses are marked with a specific color and number from the factory. Let’s say the number means “amperage”, that is, having taken out the blue one at 30 A, you need to install the same one. More or less “amperage” can subsequently lead to more serious repairs to the machine.

By the way, it is also important to find the right place to put the fuse. It happens in the dark or because of fright, drivers confuse the landing spots, which means the car may start to behave strangely. There have been cases where they confused the landing places, and then could not turn off the car with the headlights running or on. It could be anything. Therefore, if you are not confident in your abilities, it is better to turn to specialists.

What causes a fuse to blow?

The voltage of the vehicle's on-board electrical network is overloaded;
The wires of a device have short-circuited due to humidity or other sources of overload.

Through a fuse that has a belt in places where there is contact with the terminals, current will flow periodically or will be completely absent. This indicates that the contact is poor or non-existent. At the same time, it is serviceable appearance A fuse with an intact strip may not work.

Worth checking out:

If the new fuse blows immediately, you will need to do the following:

One by one, turn off all consumers that are regulated by this fuse.
To check, touch the ends of the fuse mounting terminals with a screwdriver.
If there is sparking, continue to disconnect.
After disconnecting the faulty consumer, the operating state of the circuit protection will return and the fuse will not blow (after repairing the faulty device).

Why does the fuse blow? What does this mean and how to find the cause?

Many car owners use a non-fuse wire or coin instead of a fuse. This avoids blowing a fuse, but does not eliminate the possibility of damage due to high voltage to a much more expensive device, as well as to the circuit itself. In addition, such actions increase the likelihood of fire and melting of wiring and insulation, which can lead to deterioration in the performance of the vehicle itself.