Fuses commonly used in automobiles include high current fuses and medium and low current fuses. Generally speaking, medium and low current fuses are more accessible. Low and medium current insurance can be roughly divided into chip fuse (including automatic fuse box mini fuse), plug-in fuse, spiral fuse and tube fuse box flat fuse. Among them, medium-sized ATO or small-sized fast-melting chip fuses can be contacted. Chip fuses can carry small current and short-time pulse current, such as headlight circuit and rear glass defrosting.
International standards for the colors of automotive chip fuses: 2A gray, 3A purple, 4A powder, 5A orange, 7.5A brown, 10A red, 15A blue, 20A yellow, 25A transparent and colorless, 30A green and 40A dark orange. According to the different colors, the sizes of different amperes can be clearly distinguished.
The conductor in chip fuse is made of metal similar to solder, which is lower than the melting point of ordinary wire itself. The size of the conductor should be calibrated very accurately so that when the rated current is reached, enough heat can be generated to melt the conductor and open the circuit. Fuses have two important working parameters, one is the working voltage, and the other is the rated current. The owner should choose according to the voltage and current in the circuit when buying or replacing.
Generally, there are two fuse boxes in the car. One is responsible for the safety of external electrical appliances of the automobile, such as ECU, glass water, lights, speakers, ABS and other circuits, located in the engine compartment; The other is responsible for the normal work of the electrical appliances in the car, such as cigarette lighters, window lifting, power seats, airbags and so on. , generally located on the left side of the steering wheel.