An automobile’s fuse box diagram is read as a chart that labels each fuse by its location, the electrical component it works with and how many amps it has. This diagram is generally located on the inside of the fuse box's lid. The fuses themselves are also stamped with their amperage ratings and are color-coded. Many vehicles have two fuse boxes, so consult the user’s manual to save time searching for the correct fuse box.
Always turn off the vehicle’s ignition before you open an automobile’s fuse box lid to consult the diagram. Most modern automobiles have fuses with prongs that plug easily into the fuse box. The filaments of a fuse literally fuse or burn through if a fuse is blown, which cuts the connection to the circuit. In a vehicle, this protects important parts of the electrical system and keeps them from overheating.
Common locations for an automobile’s fuse boxes are under the hood, under the dash, in the glove box or, less commonly, in the trunk. Every fuse’s amperage should match what is shown on the fuse box diagram. If you replace a fuse, it should always be the same size and color as the one you remove.