There are many electrical devices in the car circuit connected by wires of different colors, and the most important one should not be ignored is the fuse. The function of the fuse is to protect circuits (wiring) and electrical equipment. Automotive fuses work in the common DC environment in vehicles. Fuses are rated from 32 to 80 volts and have amperage ratings of 0.5 to 500 amps. They are widely used in cars, trucks, buses and off-road transportation equipment to protect the cables, wires and electrical components that power operating lights, heaters, air conditioners, radios, power windows and other electrical accessories. They are also used in electric and hybrid vehicles and various electronic applications. Typical automotive fuses include automotive blade fuses, such as automotive ATO fuses, automotive Mini fuses, automotive MAXI fuses, and automotive MEGA fuses.
automotive fuses
01 What is a car fuse
Commonly used fuses in automobiles include high current fuses and medium and low current fuses. Generally, the medium and low current fuses are easier to access. Medium and low current fuses can be roughly divided into chip fuses (including automatic fuse box mini fuses), plug-in fuses, screw-down fuses, tube fuse box flat fuses, among which the ones we can access are medium-sized ATO or small Fast-acting chip fuses. Chip fuses can carry small currents and short-term pulse currents, such as headlight circuits, rear glass defrost, etc.
International standards for automotive chip fuse colors are: 2A (gray), 3A (purple), 4A (pink), 5A (orange), 7.5A (brown), 10A (red), 15A (blue), 20A (yellow), 25A (transparent colorless), 30A (green) and 40A (dark orange). Depending on the color, you can clearly distinguish the sizes of different amperes.
The conductors within a chip fuse are made of a metal similar to solder, which has a lower melting point than the regular wire itself. The size of this conductor is very precisely calibrated so that when the rated current is reached, enough heat is generated to fuse the conductor and break the circuit. The fuse has two important working parameters, one is the working voltage and the other is the rated current. When purchasing or replacing it, car owners should choose according to the voltage and current in the circuit.
02 Types of car fuses
In order to identify the type of fuse your vehicle uses, you may need to inspect the fuse box located in your vehicle. But some fuse types are common to certain vehicles, here are the most common fuse types found in vehicles.
►Blade fuse
If the car was made after 1986, it may contain blade fuses, which are easily identified by their plastic body and two metal prongs. Although nearly all gasoline-powered vehicles use blade fuse types, they come in six different sizes with current ratings ranging from 1 amp to 100 amps.
Blade fuse
►Bosch fuses
Bosch fuses are common in older European cars and can be identified by their tapered ends and physical size of 6×25mm. These fuses are also called 6AC, GBC or torpedo fuses. This ampere rating is indicated by the color of the fuse and follows the 72581/1 DIN standard. If it's a European model from 1980 or earlier, it may contain a Bosch fuse.
Bosch fuses
► Glass Tube Fuses
Until 1986, various tubular (cylindrical) glass fuses were commonly used in American automobile manufacturing. Most of these fuses are 1/4 inch in diameter but vary in length and are designated with the AG suffix "auto glass" for example. 1AG, 3AG, 7AG, 8AG, SFE fuses, etc. The rated current of these glass fuses is usually 1A to 30A.
Although no longer commonly used in vehicles, glass tube fuses are still manufactured for a range of different applications. If it's a car made in North America in 1986 or earlier, it may contain glass tube fuses.
Glass Tube Fuses
►Lucas Fuse
Lucas fuses are mainly used in older cars assembled or manufactured in the UK. Lucas type fuses are available in ceramic fuses and glass tube fuses. Ceramic fuses are easily identified by their gauge ends, which are available in 1 or 1.25 inch lengths. Lucas glass tube fuses come in different diameter sizes compared to American glass tube fuses. However, many Lucas fuse holders do accommodate their American glass tube fuse counterparts. If it's a British model from 1986 or earlier, or a car assembled in the UK, and the fuse type is ceramic, you may want to look specifically for a LucasFuse.
Lucas Fuses
03 Blade Fuse Type
Although blade fuses come in 6 different sizes, they are divided into four main types. Each type comes in different sizes, making them easy to identify from each other.
►Maxi Heavy Duty Semiconductor Fuse
Maxi blade fuses are the largest type of blade fuses, with ratings ranging from 20 to 100 amps. Maxi Blade Fuse is the largest Blade Fuse, measuring 29.2mm wide, 34.3mm high and 8.9mm thick. Another important thing about Maxi fuses is that the corresponding rated current DIN colors are different at 25 and 35 amps, being gray and brown respectively instead of clear and teal.
►Conventional (ATO/ATC) blade fuse
This was the first portable fuse designed by Littelfuse and is still commonly found in vehicles. Their dimensions are 19.1 wide and 18.8 mm standard. Their dimensions are 19.1 mm wide, 18.8 mm high and 5.1 mm thick.
►Mini blade fuses and low profile mini blade fuses
Mini chip fuses are currently the most commonly used fuses in modern vehicles. There are also low-profile mini blade fuses, which use the same pin spacing as mini blade fuses but have a smaller plastic body. The Mini Blade Fuse is 10.9mm wide, 16.4mm high and 3.8mm thick. The Low Profile Mini Blade Fuse has the same width and thickness but is only 8.73mm tall, making it 7.5mm shorter to save space. Both fuse types are rated from 2 to 30 amps.
►Micro 2 blade fuses and micro 3 blade fuses
The smallest blade fuses currently available are microblade fuses. They are available with 2 or 3 metal terminals (prongs). Double-pin microblade fuses are called Micro2 fuses and are rated from 5 to 30 amps. They are 9.1 mm wide, 15.3 mm high, and 3.8 mm thick. Three prong micro blade fuses are known as Micro 3 fuses and are rated from 5 to 15 amps. Micro3Fuse measures 14.4mm wide, 18mm high and 4.2mm thick
Micro3 fuses are designed to protect 2 different output circuits from a single power supply. Power flows into the fuse through the center prong and out through the 2 outer prongs, and the fuse is rated for both output circuits.
04 Location of car fuses
Fuse boxes on a vehicle can be located in multiple locations, and depending on the model, make, or type of vehicle you have, there may be multiple fuse boxes.
Generally, there will be two fuse boxes on the vehicle, which contain the fuses on the vehicle. One of them is located on the right side of the engine compartment and is mainly responsible for the safety of the car's external electrical appliances, such as ECU, glass water, car lights, horns, ABS and other circuits. The other one is located on the left side of the lower part of the steering column and is mainly responsible for the cigarette lighter, The normal operation of in-car electrical appliances such as window lift, power seats and airbags. However, the easiest way to find your fuse box is to consult your owner's manual, and if your car doesn't have one, you can usually find a free copy by searching for one.
05 Car fuse replacement tutorial
If any electrical equipment does not work while the car is in use, it may be caused by a burnt fuse and needs to be replaced in time.
The method is: first turn off the ignition switch and open the fuse box cover, then replace the fuse.
Precautions:
The fuse must be replaced according to the rated current value indicated on the fuse box cover. Do not use a fuse with a higher current rating.
If the new fuse blows immediately, it means that the circuit system may be faulty and should be repaired as soon as possible.
If there is no spare fuse, you can replace it with fuses on other equipment that have no impact on driving and safety in an emergency.
If you cannot find a fuse with the same current load, you can substitute one with a lower current rating than the original fuse.
06 Frequently asked questions about car fuses
►How much does a car fuse cost?
On average, a fuse box costs anywhere from $5 to $60, depending on the retailer, what it's made of, and the type of car you drive. If a mechanic installs it, labor costs can range from $65 to $110.
►What will happen if the car fuse burns out?
Usually a blown fuse only results in minor car electrical problems, such as the backup or interior lights not working, the radio not working, loss of turn signals, or certain climate control features not working properly. But in rare cases, a blown fuse can mean the car won't start.
►What is a 30 amp fuse used in cars?
Some cars only have two fuses, a device rated about 30-50 amps that protects components wired through the ignition switch - flashers, wipers, heater motor and instruments.
►How long do car fuses last?
Typically a fuse has a shelf life/life expectancy of 10 years.
►When should a car fuse be replaced?
There is no need to replace the fuse unless it has blown, so it is not a matter of regular maintenance. When it comes to inspecting them, depending on the condition of your vehicle, many only require a visual inspection for the presence of metal.
►Why do car fuses burn out?
Faulty wiring or a faulty wiper motor can cause too much current, causing the fuse to blow, and a defective switch can cause a short circuit. Other electrical components, such as heating and cooling blower motors, power seats, electric fuel pump, or air conditioning, can cause the fuse to blow.
07 Conclusion
The above is the introduction to the types and locations of car fuses and the replacement tutorial. Although there are many reasons why you need to determine the type of vehicle fuse, the most common one is to replace the fuse. It is important to note that a blown fuse may be a sign of a larger problem with the vehicle's electrical system and a qualified mechanic should be consulted to ensure safe operation to avoid putting yourself or others at risk.
