Electrical issues can be frustrating. Something just suddenly stops working, and there’s rarely any indication of a problem. Where do you even start? Before taking your vehicle to a shop, see if the problem is tied to a fuse.

What are fuses? A fuse is a safety device consisting of a strip of wire that melts and/or breaks to disrupt an electrical circuit if the current exceeds a safe level. Fuses can take a lot of forms, from glass tubes to plastic boxes. In automotive applications, the most popular fuse type has become the blade style. These come in a couple different sizes and are color coded to signify the amperage of the fuse (or how much current the fuse can handle).

How do fuses work? Each electrical circuit in your vehicle is designed to handle a certain level of electrical power. The fuse will break, causing an interruption of the circuit, if a circuit experiences a surge of power (for whatever reason). This way, more expensive electrical parts – such as motors or switches – are unaffected by the excess power.

Testing fuses. If you suspect a fuse is blow, there are a couple ways to check them. First, you’ll want to identify which fuse is the culprit. Most of the time, owner’s manuals will possess fuse diagrams – these will tell you which fuses are on which circuits. If you don’t have the owner’s manual handy, the cover to the fuse panel often has a diagram on the back side. The location of the fuse panel differs from vehicle to vehicle, but there is almost always a fuse panel located on the driver’s side, under the steering column (with some exceptions, of course).

Once you’ve identified the fuse you need to work with, it’s time to test the fuse. Many people will simply pull out the fuse and visually inspect it. The wire within a fuse is almost always visible, so we can see fi the wire is broken. Signs of burning or melting are clear indicators of a blown fuse. However, visual inspections are not always fool proof. Luckily, we have simple tools which will test fuses without even removing them!

To use a fuse tester, you’ll align the prongs of the tester with the holds on the backside of the fuse. This allows the tester to come in contact with both ends of the fuse wire. The fuse tester is adjustable to accommodate multiple sizes of fuses. If the light on the tester lights up, that means that the fuse is good, and the circuit is uninterrupted. If the fuse if blown, the tester won’t light up. To replace the fuse, simply remove the blown fuse and install a new fuse – of the same amperage (same color) – in its place.

Most times, replacing a fuse is a simple fix for most electrical issues – and checking your fuses first can save you from costly repair bills.

Thanks to Randi M. for the question!