How to Recognize a Blown 30 Amp Fuse

No matter what size they are, fuses are very important to a car. But, like some parts of a car, fuses don’t have a set amount of time they will last. When trying to keep high energy from getting to the parts they’re protecting, they can blow off. If they let this high power through, it will hurt the electrical part they are protecting. In general, too much voltage won’t blow a fuse unless a key part draws too much energy.

What Is A 30 Amp Fuse Used For?

Fuse boxes with 30 amp ratings are used to protect electrical systems that use 30 amps from overcurrent. Some examples are the AC and the key. A 30 amp fuse works as a weak link in the electrical chain so that it can do its job as a safety device.
Therefore, when an overcurrent circuit travels to the AC or ignition, it’ll overheat and cut the metal strip that links the two fuse terminals together. Remember, this metal strip transmits electric flow from one part of the fuse terminal to the other. So, once the strip breaks, it prevents the high current from passing through and protects the key component from damage.

Generally, 30-amperage fuses are used in cars to protect 500-watt sound systems, electric radiator fans, and heater blower motors. In any case, the fuse’s amperage depends on the capacity and size of the audio system. 

Auto manufacturers and aftermarket producers design fuses in various types. If you look at the fuse boxes in your vehicle, you’ll notice that some fuses have a cartridge style while others have a blade style.

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You’ll also notice that these fuses are made with different materials and have different colors. The materials and colors show the fuse’s amperage. For example, a 30 amp fuse is pink with a light blue cover with a ‘30’ inscription on the cover. The ‘30’ shows it is a 30 amp fuse.

Electrical components in your car require different voltages. Hence, they need different amperages. For example, electrical components that require small electric flow, like taillights, horns, and brake lights, use a 10-amp fuse, while AC and ignition that use higher voltage need a 30-amperage fuse.

So, if there is an overcurrent circuit that goes to the AC or ignition, it will get too hot and cut the metal strip that connects the two fuse contacts. Remember that this metal strip moves electricity from one fuse contact to the other. When the strip breaks, the high current can’t get through, which keeps the key part from getting damaged.

Most of the time, 30-amperage fuses are used to protect 500-watt sound systems, electric cooling fans, and heater blower motors in cars. Any way you look at it, the fuse’s current depends on how big and powerful the sound system is.

Different kinds of fuses are made by automakers and aftermarket companies. You can tell the difference between cartridge and blade fuses by looking at the fuse boxes in your car.

Other things you’ll notice are that these fuses are coloured and made of different materials. The fuse’s amperage is shown by its elements and colours. In this case, a 30 amp fuse has a pink body and a light blue lid that says “30” on it. It’s a 30 amp breaker because of the “30.”

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Different parts of the electrical system in your car need different levels. Which is why they need different amps. Taillights, horns, and brake lights, which need small amounts of electricity flow, use a 10-amp fuse. On the other hand, AC and ignition, which need higher power, need a 30-amp fuse.

What Does A Blown 30 Amp Fuse Look Like?

The ends of a 30-amp fuse are connected by a wire or metal strip. It could be copper, aluminium, an alloy, zinc, or silver that makes up these metal pieces. Electricity flows to both contacts through this strip or line.

High voltage will stop the wire or strip, which will let you know if the fuse has blown. The flow of electricity is too high, and it will cut the wire or metal strip that connects the fuse contacts. The fuse will need to be replaced.

So, a 30-amp fuse that has blown or broken will look like it has a broken wire or strip running across the two metal contacts of the fuse.

This shows you what a 13a fuse or a 40a fuse looks like when it blows. A 13A or 40A fuse that has blown looks like a 30A fuse that has blown.

Fuses come in many shapes, sizes, and colours. But no matter what kind of fuse you have, they all have one thing in common: the ends are connected by a wire or metal strip. I think you should take off the cover to visually check the 30 amp fuse since they usually come in cartridge shapes.

There are clear differences between a 30-amp fuse that works and a good one. If it’s still good, there will be a metal strip between the two ends. If it’s broken, that strip will be broken because of high voltage or a bridge in one of the lines. You can see the lines. That is why it is easy to tell if it is broken.

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The main job of a fuse and switches is to do this, though. So, when there is high voltage in the line that goes with them, they blow up instead of hurting the main part of the car.


You have seen what a 30 amp fuse looks like when it blows, what it’s used for, how to test it, and how to replace it. You won’t have to wonder, “What does a 30 amp fuse look like that has blown?” All three of the above testing methods work pretty well. You can also test a 30-amp breaker that has blown without help.

Last but not least, the replacing process is quick and easy. It only takes twenty minutes to change a 30-amp switch that has blown. You should hire a trained mechanic to do the job, though, if you don’t trust your gut.

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