Auto DIY - Changing Fuses

If your stereo goes dead, a light goes out, or some other device stops working, a blown fuse is likely the culprit. A broken fuse is no cause for alarm, in fact, they are designed to break. When there is an excessive amount of electricity flowing through the circuit, the fuse blows in order to prevent serious damage or fire to your vehicle. If you have found yourself driving silently in the dark, it's time for a little DIY changing fuses.

Fortunately, fuses are inexpensive and relatively easy to replace. For convenience, some vehicle fuse panels feature slots to store extra fuses. However, if there isn’t a storage space there, the next best place store them would be a space in your glove compartment, trunk or emergency kit.

Step-by-Step Guide to Changing a Fuse

Find the panel

Consult your owner's manual to determine the location of your vehicle's fuse panel. Most manuals have a diagram showing you where each fuse box is located. Frequently fuse panels are positioned beneath the driver's side of the dashboard or in the engine compartment, but location does vary from vehicle to vehicle.

Remove the fuse panel cover

The panel will be filled with fuses. The fuses are coded by color, each color signifying a different amperage rating. The fuse panel cover usually features a fuse diagram that will indicate the required amp rating for each slot as well as the function controlled by the fuse positioned there.

Out with the old

Once you have located the fuse slot that controls the non-working component, remove the fuse and examine it for failure. Electrical current passes through the fuse via a filament made of thin wire. If the filament is broken, the fuse is most likely the cause of the problem with your component.

Some vehicles are equipped with a special "puller" to assist in the removal of fuses, but tweezers and sometimes fingers work just as well.

In with the new

Replace the blown fuse with a new fuse of the same amperage. It is important that you never replace a blown fuse with one rated for a higher amperage. A higher amp fuse allows a higher current to flow through the circuit. Too many amps can damage the circuit, the component it's designed to protect and may even start a fire. As a short term fix, it is possible to replace a fuse with a slightly lower amp rating, but it should be replaced with the proper fuse quickly as the lower amp fuse is likely to blow after only a short time. If you don't have a spare fuse, it may be possible to insert the fuse of another less-used component temporarily―as long as the rated amperage of the fuse is equal to or less than the rating of the faulty fuse.

Test the Component

After exchanging the fuse and replacing the panel cover, start the car and determine if the component has resumed operation. If it appears to be functioning correctly, it is most likely that your car experienced a temporary current and, per design, the fuse blew to protect the component. However, if during this process the fuse filament appears to be intact or the fuse blows again immediately after replacement, attention from a mechanic will likely be required.