How to Spot a Blown Fuse in Your Vehicle

Fuses are an important part of automotive electrical systems. Regardless of what type of vehicle you drive, it probably has fuses. Some vehicles have 20 fuses, whereas others have over 60 fuses. Fuses, however, can blow. That's essentially how they protect electrical devices from failure.

If too much current is flowing to an electrical device, the fuse will blow. The wire filament within the fuse will melt, thereby breaking the circuit. As a result, the electrical device won't sustain damage from a sudden and excessive surge of current. Blown fuses, of course, should be replaced. How do you know if your vehicle has a blown fuse?

Electrical Device Failure

You may not be able to use one of your vehicle's electrical devices if it has a blown fuse. All fuses are connected to an electrical device. There's typically a fuse for the radio, the cabin lights, the headlights, the air conditioner and more. When a fuse blows, the electrical device with which it's used won't receive power from your vehicle's battery. This means the electrical device will stop working. To get it working again, you'll have to replace the blown fuse.

Broken Wire Filament

If you believe your vehicle has a blown fuse, you should inspect the fuse box. The fuse box is a container that houses all or most of your vehicle's fuses. You can usually find it in the engine bay or underneath the dashboard of your vehicle's cabin To determine whether a fuse is blown, open the fuse box and inspect the wire filament of each fuse.

Fuses feature a wire filament. The wire filament is conductive so that current can flow through them. But they only allow up to a specific amount of current to flow through them. If there's too much current present, the wire filament within the fuse will melt and break from the excess heat. If you notice a fuse with a broken wire filament, it's probably blown and, therefore, should be replaced.

Replacing a Blown Fuse

Fortunately, blown fuses are easy to replace. You just need to pull out the blown fuse and replace it with a new fuse of the same type.

Keep in mind that fuses are available in different sizes and amperage ratings. When replacing a blown fuse, you should choose a new fuse in the same size and amperage rating. Choosing the wrong type of fuse could result in damage to the connected electrical device.