Fuses are a safety device that can turn off the electricity. Fuses are designed to interrupt the flow of electricity when some condition occurs that would cause an excessive amount of electricity to flow. The primary function of a fuse is to prevent fire but they also protect sensitive electrical equipment. There are several different types of fuses that in vehicles today but they all operate in the same way. Fuses can be a cylinder of glass and plug in fuses are also popular.
The fuse has a fusible link inside made of a special type of metal that melts at a fairly low temperature. The fusible link inside the fuse heats up just like the wire does when electricity flows through it. If something goes wrong and suddenly a lot of electricity starts flowing in the wire, the fuse heats up to its melting point and melts. The fuse interrupts the flow of electricity and prevents damage to our wires and equipment.