Things to Know About Replacing a Burned-out Fuse - Subaru Service Questions in Salt Lake City, UT

The electrical components in your car are protected by fuses. These handy components are designed to prevent electrical damage. If one of the wires in your car has too much current flowing through it, the fuse prevents the excess electricity from causing bigger problems. It does this with a metal filament that burns out. This then breaks the circuit so that the broader system won't be damaged. If the extra current was due to a fluke, it may be that simply changing the fuse fixes your issue. You'll find out exactly how to change a fuse below. But keep in mind that a blown fuse may just be a symptom of a larger problem. If the fuse blows again shortly after being replaced, it's a sure sign of a deeper problem that will probably require expert investigation.

Fuse box with fuses

Step 1: Check the Owner's Manual and Turn Off the Engine

Before you get to any actual fuse-changing, you need to see which fuse needs to be replaced--and your owner's manual can help with this. Most vehicles have two fuse boxes: one on the driver's side of the instrument panel and one under the hood. Typically, the owner's manual will have a diagram of both of these boxes, with each fuse labeled so that you can find the one that needs to be replaced.

Fuse held up to light, with broken filament inside

Step 2: Turn Off the Engine & Disconnect the Battery

Before you start working on any automotive project, it's important that you turn off the engine and disconnect the battery, especially before doing any electrical work. Any misstep with automotive wiring while the battery is hooked up could cause further damage and potentially give you an unpleasant zap. Additionally, keep basic safety measures in mind, like properly securing the vehicle from rolling unexpectedly, anytime you're working on a vehicle. Of course, it may just be easier to have certified technicians take care of it.

Step 3: Open the Fuse Box & Find the Fuse

Once the engine is off and the battery is disconnected, use the fuse box diagram to locate the right fuse. It might be a good idea to keep the owner's manual with you, so that you can double-check and make sure you've found the right fuse. Another suggestion is to find the fuse puller designed specifically to safely and easily remove fuses. Most modern cars have such a fuse puller in the fuse box under the hood or under the dash. If you don't see the fuse puller, a set of needle nose pliers can work as long as you're not working on an older car with Bus fuses that look like little glass cylinders.

Person putting a fuse into the fuse box

Step 4: Remove & Inspect the Fuse

With the fuse pullers or pliers in hand, it's time to remove the fuse. Make sure the tool is gripping the fuse firmly, and then pull straight out. Once you have the fuse in hand, hold it up to a light source and take a look through the translucent plastic. If it's a blade-type fuse, as most fuses in your vehicle will be, then you'll be able to see a metal wire inside. If this wire is intact, then your electrical woes are being caused by something else. But if it's broken, that means the fuse has blown.

Step 5: Insert the New Fuse

Inside the lid of the fuse box, you should find spare fuses with a variety of amperage ratings. It's important that you replace the old fuse with a new one of the same amperage. Failure to do so can cause even more electrical problems by overloading the circuit. Blade fuses are color-coded, and the amperage rating is printed on each one. Once you've replaced the fuse, put everything back the way it was, and then cross your fingers as you discover whether the fuse really was the cause of your problems.