Fuses are essential electronic devices in automobile circuits. Automotive fuses are widely used in cars, trucks, buses and off-road transportation equipment. In vehicles, automotive fuses serve to protect electrical circuits (wiring) and electrical equipment, such as 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. Automotive fuses generally operate in a DC environment, and they are typically rated from 32 to 80 volts and have amperage ratings of 0.5 to 500 amps.

1.What is automobile fuse

The conductor inside the chip fuse is made of a solder-like metal that has a lower melting point than the regular wire itself. The size of this conductor is calibrated very precisely so that when the rated current is reached, enough heat is generated to fuse the conductor and break the circuit. Fuses have two important operating parameters, one is the operating voltage and the other is the current rating, and the owner should choose one based on the voltage and current in the circuit when purchasing or replacing it.
Commonly used fuses in automobiles include high current fuses and low and medium current fuses, which are generally easier to access as low and medium current fuses. Low and medium current fuses can be broadly categorized into chip fuses (including automatic fuse box mini fuse), plug-in fuses, screw-in fuses, tube fuses, flat fuses, of which we have access to the medium-sized ATO or small fast-melting type chip fuses. Chip fuses can carry small current, short time pulse current, such as headlight circuit, rear glass defrost, and so on.
The international standards for automotive chip fuse colors are: 2A grey, 3A purple, 4A pink, 5A orange, 7.5A coffee, 10A red, 15A blue, 20A yellow, 25A clear colorless, 30A green and 40A dark orange. Depending on the color, you can clearly distinguish between different amperage levels.

2.Types of automobile fuses

In order to identify the type of fuse used in your vehicle, it may be necessary to check the fuse box located in your vehicle. However certain fuse types are common to certain vehicles, the following are the most common fuse types found in vehicles.

2.1 Blade Fuses

If the vehicle was built after 1986 it may contain blade fuses, these are easily recognized by their plastic body and two metal pins. Although blade fuse types are used in almost all gasoline-powered vehicles, they are available in six different sizes with current ratings ranging from 1 amp to 100 amps.
Blade fuse types are categorized into four main types, automotive ATO fuses, automotive Mini fuses, automotive MAXI fuses, and automotive MEGA fuses. Each type has a different size, making them easily recognizable from each other.

2.2 Glass Tube Fuses

Until 1986, a variety of tubular (cylindrical) glass fuses were commonly used in automotive manufacturing in the United States. Most of these fuses were 1/4 inch in diameter, but varied in length and were designated “automotive glass” with an AG suffix, e.g., 1AG, 3AG, 7AG, 8AG, SFE fuses, etc. These glass fuses were typically rated from 1A to 30A.
Although no longer commonly used in vehicles, glass tube fuses are still manufactured for a range of different applications. If the vehicle was built in North America in 1986 or earlier, it may contain a glass tube fuse.

2.3 Bosch Fuses

Bosch fuses are common in older European cars and can be recognized by their tapered ends and physical size of 6 x 25mm. These fuses are also known as 6AC, GBC or Torpedo fuses. This amperage rating is indicated by the color of the fuse and follows the 1 in 72581 DIN standard. If it is a 1980 or earlier European model, it may contain Bosch fuses.

2.4 Lucas Fuses

Lucas fuses are mainly used in older cars assembled or built in the U.K. Lucas type fuses are available as ceramic fuses and glass tube fuses. Ceramic fuses are easily identified by their specification end and are 1 or 1.25 inches in length. Lucas glass tube fuses have different diameter sizes compared to American glass tube fuses. However, many Lucas fuseholders do accommodate their U.S. glass tube fuse counterparts. If it is a 1986 or earlier UK model, or a car assembled in the UK and the fuse type is ceramic, you may need to look specifically for a LucasFuse.