Car Fuse Facts: What You Need to Know About Automotive Fuses

Written by

CarParts.com Research Team

Automotive and Tech Writers

Updated on November 18th, 2024

Reading Time: 6 minutes
Summary
  • Blade-type fuses are most commonly used in automotive applications.
  • They have two metal blades designed to insert into the fuse block. The other end has a plastic-covered element.
  • Fuses are color coded according to the amperage they can handle. They circulate electrical current to power vehicle parts and accessories.
  • It is possible for a car fuse to go bad without blowing. Although it rarely happens, it’s possible for its metal parts to corrode.

Your vehicle has many different circuits that power everything from the radio to the engine computer. If one of those circuits suddenly stops working, it may be due to a blown fuse. A fuse serves as a shield against electrical shorts and other problems that could lead to excess current flow mishaps.

A fuse blows when a short circuit or other issue takes place somewhere in your electrical system. It means it has done its job to protect your vehicle from further equipment or wiring damage. A blown fuse may also mean that you have an electrical or wiring issue that needs to be repaired immediately.

Can A Fuse Go Bad Without Blowing?

It is possible for automotive fuses to go bad without blowing. They may become corroded due to moisture, but it very rarely happens. Most of the time, they just get blown. Even if fuse corrosion almost never happens, your automotive fuses are still worth checking out routinely to make sure they’re all good.

Your vehicle’s various fuses serve as shields against electrical shorts and other problems that could lead to excess current flow mishaps.

What Is a Fuse Made Of?

There are different types of fuses used for different applications. However, blade-type fuses are commonly used in modern vehicles. They have two metal blades, which are designed to insert into your fuse block. The other ends have an element in between them, which is covered in plastic. Each blade-type fuse is color coded according to the amperage it can handle. It uses a durable material to connect its blades, making sure that it lasts a long time. Metals, such as copper, aluminum, or silver, are usually used because they can withstand their intended current capacities.

Why Is It Important For Your Car to Have Fuses?

Car fuses may be more important than you think. Without them, overloaded electrical currents may cause your wires to overheat and melt. Other electrical components may get damaged, as well. Overloaded wires may ignite and cause car fires, which may injure or harm vehicle occupants. Fuses prevent strong electrical currents from flowing into wires or devices that can’t handle them.

However, they can only protect your vehicle if they have the right capacity. A fuse’s capacity is influenced by wire size and amperage, which may vary based on your electrical devices. It’s important to take note of amperage whenever you’re replacing or adding electrical parts to your car. Your devices and automotive fuse types must have matching capacities to make sure your vehicle is safe against unexpected short circuits and electrical problems.

What Does a Fuse Do?

If your electrical system is in good condition, it circulates a steady electrical current to power your vehicle’s parts and accessories. However, wiring complications or other electrical issues may cause sudden spikes of electrical flow, which may become damaging to your vehicle.Your fuses are basically designed to blow as a preventative measure.

If the electrical current flowing through the circuit is greater than your fuse’s rating, it stops the current before it causes trouble. However, the time it takes to blow may vary. It depends heavily on the material used on your fuse and how excessive your electrical current is. If your fuse blows, it’s best to get your vehicle checked. You may easily replace your blown fuse and get your car back on the road. However, an underlying electrical problem may have caused it, which can lead to recurring blown fuses or further electrical damage.

You’ll be able to tell that a fuse has blown if its internal element is broken.

How to Tell If a Car Fuse Is Blown

The first sign of a blown fuse is when an electrical device suddenly stops working. It may be caused by other complications, so you can’t say for sure unless you check your car for a blown fuse. It has many fuses that are all housed in different fuse boxes, which are in various locations within your vehicle. Before you can open it up, you need to check your owner’s manual to make sure you have the correct fuse box. It has a diagram with your fuse boxes, their exact locations, and the name of each fuse. Once you open and investigate it, you’ll be able to see if the fuse connected to your device is burnt out or blown.

What Does a Blown Fuse Look Like?

It’s easy to determine a blown fuse visually. You’ll be able to tell that a fuse has blown if its internal element is broken. However, it may not be the only one that burnt out. It’s common for multiple fuses to blow at the same time, so make sure you thoroughly check on other fuses in the box to determine the extent of the damage. You should also take note of the capacity of the blown fuse so you can get the right replacement fuse.

You may also use a multimeter to check for continuity flowing through your fuse if you have one. It’s good to double-check to see if your fuse is still working or if you need to replace it. Just make sure you remove it from the fuse box before testing it out so you don’t damage your meter. You can also consult a professional to get an accurate diagnosis.

What Causes Blown Fuses in Cars?

A blown fuse is generally caused by unstable electric current that may become too strong for your vehicle to handle. Excessive current flow is typically caused by:

Faulty Wiring

Your wiring has to be in good condition to efficiently deliver electricity where it’s needed. However, wires may wear out or become faulty over time. Some vehicles may also come with improper or defective wiring, which may make your vehicle more prone to blowing a fuse. If you suspect your vehicle has faulty wiring, don’t hesitate to ask a mechanic for help. Running tests and getting diagnostics may require special tools, which may be troublesome to acquire on your own.

Defective Parts

Defective windshield motors, switches, and other electrical parts are common causes of a blown fuse. Flawed components may cause sudden surges of electrical currents or short circuits, which may burn out your fuse. If you think faulty parts are causing your blown fuses, take your vehicle to a mechanic for an inspection as well as a part replacement as needed.

Your electrical system is crucial to making your vehicle function normally. Make sure your fuses are working properly to keep your car protected from dangerous electrical complications.

How To Replace Blown Fuses

Before replacing any of the fuses in your vehicle, make sure you have the following items:

  • Electrical gloves
  • Fuse pullers or pliers

To replace any blown fuses in your vehicle, follow these steps carefully:

  1. Turn off the engine and disconnect the car battery.
  2. Locate your vehicle’s fuse panel. If you can’t find the fuse panel, consult your vehicle owner’s manual.
  3. Remove the cover of the fuse panel and peruse the fuses inside. Each fuse is associated with different colors and numbers.
  4. Keep a sharp eye out for the blown fuse. A blown fuse is typically black or has broken metal filaments.
  5. Remove the blown fuse from the panel with pliers or fuse pullers.
  6. Insert a replacement fuse with an appropriate amperage.
  7. Reconnect the car battery and turn on the engine. See if the replacement fuse works properly and replace it again if it blows.

Fuse Replacement Tips

Here are some handy tips you should always keep in mind if you plan on replacing blown fuses.

  • Don’t forget to turn off the engine and disconnect the car battery to avoid getting shocked.
  • Keep replacement fuses of various amperages ready in your glove box in case you need to change them on the road.
  • Always keep electrical gloves and fuse pullers in your vehicle.
  • Blade-style fuses should be pushed by hand to minimize the risk of breaking them.
  • Bring a flashlight with you when replacing fuses to help you spot blown fuses and other anomalies.

How to Get Replacement Fuses for Your Vehicle

If you think driving around with a blown fuse is a good idea, think again. A blown fuse is likely to mess with your vehicle’s electrical systems and cause your wires to overheat. This can lead to further damage that won’t be cheap to fix. Luckily, you can save yourself the trouble by getting a brand-new fuse from CarParts.com today. 

CarParts.com offers a wide selection of fuses, all sourced from the most trusted manufacturers in the industry. You can easily browse through them by using our search filters and vehicle selector. Just be sure to enter your vehicle’s correct details. CarParts.com also guarantees fast shipping, thanks to our strategically located warehouses around the US. Order by 12 p.m. ET, and you can expect your new fuse to arrive in as fast as two business days.

Don’t wait until your car fuses to go bad before replacing them. Check out our catalog of high-quality fuses at CarParts.com today!

Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.