How To Tell If A Fuse Is Blown? Explained

To tell if a fuse is blown, look for the dark burn marks or check the link between the two terminals. If the link or prong is broken, then your fuse is blown. This is the most simple way for you to detect a blown fuse through visual inspection. 

Alright, so you have successfully found your fuse box and opened it. But you still can’t find that blown fuse. 

Now, how to tell if a fuse is blown?

But you can also find out about your blown fuse through looking for different symptoms. To know more about these and how to replace your fuse, let’s get started. 

How To Tell If A Fuse Is Blown?

The most obvious step is to just look for it. Of course, you can test your fuse with a multimeter. Not only that, you can even test a fuse without a multimeter. But let’s focus on the easy method here. Visual Inspection.

Now, this is how a blown fuse looks like in a car. The pictures below show the comparison between a blown and an intact fuse. You can definitely visually inspect your fuses and find out if the fuse is blown or not.

Pull out the blown fuse and it will look like the following 

  • Dark burn marks around the fuse

Image Source: YouTube

  • Links inside the fuse case is broken

Image Source: Fuse-box.info

The link between the two blade terminals or prong is broken on the right fuse. 

What Are The Symptoms Of A Blown Fuse?

Car fuse blown symptoms depend on the fuse that has been blown. For example the symptoms for a blown cooling fan fuse will be different from blown battery fuse. 

Let’s go through some of the fuses and find the symptoms for each. 

Blown Cooling Fan Fuse

Whenever the cooling fan fuse blows up, your car’s thermal system is affected. These are the symptoms you may face in that case. 

Engine Overheating

It means the cooling or radiator fan is not working. Without a cooling fan, the engine heats up rapidly and that leads to engine overheating. 

Air-conditioners Not Working Properly 

The air conditioner’s condenser sits in front of the cooling fan and acts like a heat exchanger. Without proper airflow, the condenser fails to release the heat from the AC’s core. This means the AC is not working properly. 

Blown ABS Motor Fuse

Following are some of the symptoms of a blown ABS motor fuse. 

ABS Warning Light Coming On

ABS Warning Light turns on whenever there is any problem with the ABS. Whether your wheel speed sensors are not working or if there is any problem with the brakes themselves. But a blown fuse will also cause the ABS Warning Light to turn on. 

Wheel Locking

If this fuse is blown then there is a disruption in the electrical flow. Due to this disruption, your anti-lock braking system can’t work properly. So, if you need to apply brakes the ABS will not be able to work despite functioning brakes. 

Longer Braking Distance

When the ABS fuse is blown, the braking system stops working. So, when you try to hit the brakes, the wheels lock up as mentioned on the previous point and it skids. The result is longer braking distance.

Definitely, make sure to diagnose any braking related issue and solve it as soon as possible. 

Other Fuses

Following are some of the symptoms that will help you to detect a few other blown fuses.

Blown Turn Signal Fuse

When the turn signal fuse is blown, it disrupts the power flow from the junction box. Without this electric power, your turn signal cannot function. Even if you use your turn signal lever or hazard light button, it won’t function.

Blown Dashboard Fuse

If the dashboard light fuse is blown then your lights will not work. Of course, there are a few symptoms you need to look out for. But beyond that, you should look for other components in the dashboard like the light bulbs, and dimmer switch. 

Blown Power Window Fuse

This one is quite obvious but a damaged power window fuse means that your power window will not work.

Blown Radio Fuse

If your radio system stops working all of a sudden then you need to diagnose and check if it is the fuse behind this problem. 

How To Replace Your Fuse?

Lucky for you, the solution to all the fuse related problems in your car is just replacing it. Following are the steps for replacing the fuse in your car

Step 1: Firstly, turn off the car engine and make sure that battery is disconnected. Now, find the car’s fuse panel. It should be near your steering wheel or under the hood, but check your user manual to find it out. 

Step 2: Next, you have to take off the fuse panel cover. There should also be a diagram that shows what each of these fuses power in the car.

Step 3: Remove the fuse either using the fuse puller provided in the fuse box or with a pair of nose pliers.

Step 4: Take note of the ampere of your blown fuse and insert the new fuse. Again, make sure that the newly placed fuse matches the exact amperage.

Step 5: Now, put the fuse panel cover back in its place and start the engine. Check if the fuse is working properly or not. 

Step 6: However, if the fuse is not working despite replacement, either you haven’t replaced it properly or there is a bigger issue like a faulty motor or wiring that needs replacement. Consult a professional in that case.

Cost of Fixing Car Fuse  

It should cost you around $75-$120 to get your fuses replaced. An average fuse will be $10-$20 and $65-$100 is the labor cost depending on the state you live in. 

How To Protect Your Fuse For A Long Time?

The following maintenance steps will will prolong your fuses’ lifespan:

  1. Use the exact amperage of the fuse. If the requirement says 15 A, use that. Do not put 30 A or 10 A. You will either damage your component or keep blowing the fuse.
  2. Check the wiring in your car. Any wiring whether it is ECU or the battery, faulty wiring is one of the main reasons for short circuits and fuse blowing. So, keeping your wiring intact can protect your fuse.
  3. Protect the switches and replace any damaged switch as soon as you can. Because defective switches will eventually lead to blown fuses. 
  4. Make sure to always use the OEM components and don’t add any part with a higher wattage. 

With that pointed out, we hope that you will be able to tell if a fuse is a blown plug and replace it as well. You should also know how to keep your car fuses protected for a long time. 

FAQs

Is Fuse and Relay The Same?

No, fuse and relay are not the same. Fuse is a safety device whose function is to protect the electronic circuit. It does that through blowing itself whenever there is any overcurrent. Whereas relay acts as a switch, where it turns on or off the electronic circuit based on the situation.

Why Is The Fuse Not Working After Replacement?

Fuses do not work after replacement due to malfunctioning motors or other electrical components that require more electricity. Whenever that happens your fuse will keep getting damaged despite regular changes. In that case, your system will keep having short circuits. 

Will Using The Lower Amperage Fuse Cause Blowing?

Yes, if you use a lower amperage fuse, it will blow. For example, if you replace a 25 amp fuse with a 15 amp fuse, the current flow will still be for 25 amps. But the 15 amps can’t handle that much current and so it will blow. 

Conclusion

With that knowledge you know how to tell if a fuse is blown. Remember to do the visual inspection properly. Depending on the outcome you can test it with or without a multimeter. If it is actually damaged, replace it. All of these are actually very simple. 

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William Baldwin

This Is William Baldwin, The Founder & Managing Editor of this website. Me and my team share automotive tips, tricks, and news

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Talha

Talha Atta

Talha Atta, a Mechanical Engineer and experienced technical content writer and editor at Autoglobes.com with a passion for the automotive industry.