How To Test Car Fuses

How To Test Car Fuses – Doing It The Right Way

by Samuel Gitukui

Before we can find out how to test car fuses let’s first determine what is a fuse. Fuses are safety devices that shield an automobile’s electric circuits from an excess of current (overloading).

A wire that is overloaded could melt or catch fire without a fuse. A separate fuse protects each circuit. Electric power steering and radiator fan circuits, for example, are protected by a number of larger fuses with high Amp ratings.

Additionally, there is at least one primary fuse. Additionally, you can locate the fuse removal tool in the fuse box or in the cover of the fuse box.

Checking the fuse that safeguards the circuit with the problematic electrical component is the first thing to perform when anything in a car stops working. Fuse boxes in modern vehicles often have two locations: one within the cabin and one under the hood.

The owner’s manual and the fuse box cover both contain the fuse map. There are various methods for checking fuses. The simplest method is to remove the fuse and visually inspect it; the owner’s manual for your car contains instructions on how to do this.

Test Light

Test Light

A test light is an instrument that detects voltage in a circuit visually. It consists of two test leads connected to a bulb.

Neon test lights are the most popular test lights. A neon test lamp employs two electrodes to ionize the neon gas inside of a bulb that is full of the gas.

Because neon bulbs last longer than other bulbs, many prefer neon test lights.

Because of their extremely high resistance, neon bulbs have a very long lifespan and use very little current while measuring. When voltage is present in the circuit being tested, the test light’s bulb lights.

Advantages And Disadvantages Of Test Lights

The advantages of test lights include their low cost, portability in a pocket, and ease of use on how to test car fuses.

The drawback of test lights is that they only support a small range of voltages and can only detect the voltage that is already present in a circuit.

Better test lights than test lights with only one voltage rating have a wider voltage range.

A neon test lamp rated for 90 VAC to 600 VAC, for instance, performs better than one rated for only 120 VAC.

Another drawback of neon test lights is that they cannot test ground fault circuit interrupters (GFCIs) or ground fault interrupters (GFIs) since, when connected between the hot side of the receptacle and ground, the neon bulb does not draw enough current to trip the GFCI.

Blown Fuse

Fuse safety devices prevent current overload in electronics, which could harm an electrical circuit. A fuse is often a strip of metal wire that melts or burns when an excessively high current flows through it, breaking the circuit to a particular device and preventing the flow of energy.

Such fuses are common in automobiles to safeguard their various electrical systems from high voltage incidents. These fuses are typically located in one of two fuse boxes for most vehicles and have a 32-volt rating.

The most frequent cause of a car component failing is typically a blown fuse due to an excessive amount of electrical current.

This could apply to commonplace driver-interface components like a car stereo or interior lighting, as well as more complex electrically powered systems like the electronics in the powertrain and chassis, safety features, driver assistance technologies, and amenities for the comfort of the passengers.

You can locate the defective fuse and replace it when a failure occurs. Online and at practically every retailer with an automobile section, replacement fuses are available.

Why Do Fuses Blow

A blown fuse will indicate a short circuit. When gadget malfunctions, an electrical component can draw more current than it can handle.

Fuse blowing is frequently a result of defective switches and poor wiring, but any mechanical problem with a motor or electrically driven moving item could be to blame.

For instance, the motor may short out due to a windshield wiper that is trapped in the ice. The blown fuse in this instance keeps the motor from overheating and burning out, which would require a far more expensive replacement than the fuse.

The logical first step to solve an issue is to check the fuse in instances of typical failures, such as with lights, power seats, or air conditioning.

However, for a vehicle’s more intricate technical systems, it is advised that the owner looks into the cause of the blown fuse because it might be a sign of a bigger problem that could get worse even after the fuse has been changed.

It is suggested that you speak with a licensed mechanic or the dealer service department.

Finding A Blown Fuse

When you think a fuse may have blown, turn off the engine and look for the main fuse box. Most frequently, it is located in the footwell beneath the dashboard on the driver’s side.

Under the hood, there can possibly be another fuse box. For information on each’s precise position, refer to your owner’s handbook.

In most cases, the fuse box contains a diagram that shows you the location and name of each fuse. This will assist you in locating the fuse linked to the broken car part. But be sure to study the graphic carefully because a regular automobile might have more than 30 fuses, and more expensive cars with more electronics might have two or three times that number.

Once you’ve located the correct fuse, remove it (preferably using fuse pullers or pliers) and give it a visual inspection. The wire element inside the fuse will have burned or melted due to the increasing electrical current, making the blown fuse obvious.

To find the dead fuse without having to pull it out, you can also use a test light or a multimeter. This is thus a great tool when wondering how to test car fuses. Both gadgets are inexpensive and simple to use.

Changing The Fuse

Get a replacement fuse that is the same as the one you’re replacing after making sure the blown fuse is the culprit. Vehicle fuses often come in one of three shapes: cylindrical glass fuses, cylindrical plastic fuses, or square plastic fuses with twin prongs.

They all make use of breakable or burnable filaments. Because replacing a fuse with one of a different voltage can harm the component the fuse is meant to protect, it is crucial that the new fuse is of the same type and voltage.

Simply replace the old fuse with the new one, making sure to fully enclose it. You can quickly determine whether it is properly set by comparing it to the fuse adjacent to it.

Put the fuse box panel back in its original setting after which you should start the car. After learning how to test car fuses and installing the replacement fuse, check to see if it still functions.

If it does, the substitution was successful. If it doesn’t, get in touch with a mechanic to further investigate the problem.

Fuses For Car

Fuses For Car

Car fuses help to safeguard the wiring in vehicles. They provide protection from short-circuiting and overcurrent by cutting the circuit off if they notice a potentially hazardous amount of current. Also, they are additionally sometimes called automotive fuses.

There are several kinds and sizes available, and each is ideally suited to various uses as well as electrical equipment within a car.

The majority of fuses in current cars are blade-type. This indicates that they have a comparable design, distinguished by a body made of colored plastic as well as two prongs that fit into a socket.

Depending on the application, they are located in the fuse blocks, the fuse clips, or even the fuse holders.

How To Test Car Fuses – How To Examine A Car Fuse

Single-use auto fuses shouldn’t normally need to be replaced unless that is, they are damaged. Because of this, routine maintenance is typically unnecessary, and, in the majority of cases, a quick visual inspection will be enough to identify whether the fuse is still functional.

The wire will be severed in the event of a blown or broken fuse, and will typically be clear whether the connection has cracked or melted.

You can use a multimeter to evaluate the fuse’s state if inspecting visually is difficult to do or if further evidence is required. There are two ways to accomplish this:

Attach the probes to the fuse’s ends using the multimeter’s continuity mode. This enables the tool to check for electrical continuity throughout the fuse and perform an electric test. Simply finding out how to test car fuses will help you do this.

The fuse is most likely blown if you notice the multimeter shows a significant resistance reading or shows an error (which will depend on the particular model of the multimeter in use.

The second way is to measure the fuse’s resistance using the multimeter’s ohmmeter setting.

Please take note that before obtaining this measurement, the fuse needs to be removed from the fuse housing or fuse box. Put the probes again on the fuse’s ends.

Usually, a low value near zero indicates the circuit is continuous. It also shows that the fuse is operating as it should. A high resistance value, or high reading, however, will indicate a problem and a blown fuse.

Automotive Fuse Types

It can be useful to become familiar with the various types of fuses that your automobile has if you have just begun driving or recently bought a new vehicle.

Your electrical system depends on fuses to function properly, so if one of them blows, you should find it and replace it right away. As we examine the many fuses that you might run across, please continue reading. We also talk about what they do and how to alter it.

1. Blade Fuses

Characteristics: Flat and thin form in various amps and sizes

Uses: Frequently seen in cars.

Amperes: 2–80

The blade fuse is one of the most typical kinds of vehicle fuses that you will probably come across. It is flat and comes in a variety of hues, such as blue, red, orange, yellow, green, and brown.

Two or three flat metal legs that protrude from the colorful plastic shape will serve as the contact points. These come in any value up to 80 amps and offer protection for small- to medium-sized wires.

Blade fuses are simple to understand and don’t roll away like round fuses. Six sizes of blade fuses are offered: Micro2, Micro3, Low Profile Mini, Mini, ATO/ATC, and Maxi. This type of fuse’s only drawback is that it eventually burns out, at which point you will need to replace it.


  • Do not roll away
  • Simple to read


  • They’ll eventually wear out

2. Cartridge Fuses

Features multiple shapes, though frequently round.

Uses: Frequently seen in cars.

Amperes: 35–60

Cartridge fuses are common in automobiles and are located in other places, such as the home. They are easy to replace, have a straightforward design, and operate quickly regardless of temperature. Cartridge fuses are well-tested, affordable, and widely available because they have been in use for a long time.

Like with blade fuses, the negative of cartridge fuses is that you will need to replace them if they face too much power. Another drawback is that they are less adaptable than blade fuses because you can only select values between 35 and 60 amperes.


  • Inexpensive
  • Simple to read


  • Eventually wears out
  • There are fewer ampere options than blade fuses.

3. PAL Fuses

Features: Female, rectangular, or bolt-on terminals

Uses: Prevalent in Japanese automobiles

Amperes: 20–120

Special cartridge fuses called PALs are very common in Japanese cars. You will likely find them on power-intensive circuits because they can handle a lot more amps than standard cartridge fuses can. The color coding of these fuses makes identification simple.


  • A strong power rating
  • Use of color-coding


  • Some require screws to be installed.

4. High-Current Fuses

Numerous shapes, but frequently rectangular, with metal tabs on the sides.

Circuits that require a lot of power

Amperes: 50–200

High-current fuses can be any size or shape, much like cartridge fuses, but they are most typically square or rectangular with metal contact posts protruding from the sides. When installing a new fuse, you frequently need to screw these tabs in place. They can withstand 200 amps. These fuses are frequently located in power-hungry circuits of non-Japanese vehicles. Usually, by seeing their hue and comparing it to a chart, it is simple to ascertain their value.


  • A strong power rating
  • Use of color-coding


  • Typically need screws to hold in place

5. Circuit Breaker

Characteristics: Thicker and more similar to blade fuses

Uses: Replacing conventional fuses

Amperes: 15–60

In contrast to your home’s circuit breaker, a circuit-breaking fuse allows you to reset it so you don’t have to change it when it trips. Even some cars may come with the standard. It is a wonderful option for circuits that trip regularly because it has a blade fuse-like appearance but is significantly larger to accommodate the tripping mechanism. It is simple to read the value because of the huge surface area.

The enormous size of the circuit breaker fuse could make it challenging to operate in some circumstances, and it will probably cost more.


  • Reusable
  • Simple to read


  • Expensive
  • Big size

Fuse Replacement Car

Fuse Replacement Car

Fuses are crucial parts of electronic devices. Fuse boxes protect the various electronic components in your car from sudden power surges. In the event that something similar occurs, the fuse will “blow” and prevent any additional electricity from reaching the specific device. Anyone with little to no experience can replace a fuse because it is so simple to do so.

How To Test Car Fuses, Replacement Process – Steps 1

Shut off the vehicle. Turning off your car is the first and most crucial step before performing any electrical repair on it.

How To Test Car Fuses, Replacement Process – Step 2

Look for the fuse box. You can now continue your search for the fuse box. The majority of the time, it is either under the glove box or inside. Nothing should require disassembly in order for you to access it.

However, there will be a cover that you can simply snap open without using any equipment. Many vehicles have many fuse boxes. There’s a possibility that the person you’re looking for isn’t in the vehicle. In this instance, the engine compartment is probably where it is.

How To Test Car Fuses, Replacement Process – Step 3

Locate the cover. Find the cover and remove it once you locate the fuse box. There must be a manual describing the purpose of each fuse. Usually, there is printing directly on the cover.

How To Test Car Fuses, Replacement Process – Step 4

Track down the blown fuse. You will be able to immediately recognize the fuse that needs to be changed if you have ever seen a standard light bulb that has burned out.

Because the metal strip within will break, it will look remarkably similar. The fuse may also be somewhat discolored aside from that.

How To Test Car Fuses, Replacement Process – Step 5

Eliminate the fuse. If it seems stuck or is too difficult to grasp with fingers, you can use a small screwdriver or, ideally, the “fuse remover” that many automobiles come with. However, it should be simple to simply squeeze it with your fingers. One of the slots should contain this remover.

How To Test Car Fuses, Replacement Process – Step 6

Don’t discard the fuse. You can either check its specifications and order one online, or you can take it to a specialized store and ask for a replacement.

How To Test Car Fuses, Replacement Process – Step 7

Change the fuse. Push the replacement into the slot where the old one was. It ought to be simple to snap into position.

How To Test Car Fuses, Replacement Process – Step 8

Verify everything. Once the fuse has been replaced, it is time to start the car and check to see whether whatever the fuse was in charge of, such as your radio, interior lighting, or fan, is now functioning.

How To Test Car Fuses, Replacement Process – Step 9

Swap out the cover. Put the fuse box cover back on after making sure everything functions appropriately.

Blown Fuse In Car Symptoms

Blown Fuse In Car Symptoms

Some individuals may not even be aware that they have a blown fuse until they observe that:

  • The backup lights are faulty
  • The interior lighting is faulty
  • The electric side mirrors do not turn
  • Radio malfunctions
  • There is no turn signal light.
  • The window washer is immobile.
  • Climate control is acting up.
  • Your heating and cooling fans are ineffective.
  • There was a “day off” for the air conditioning
  • The power seat has lost its “power”
  • You can’t get fuel from your electric fuel pumps.
  • You can’t even start your car (very rare case)

The first thing to do if a car fuse has recently blown is to consult your owner’s manual to determine which electrical circuit it is a part of. It is typically not a problem if you change a fuse and a problem does not arise.

But if it blows once more, it can be a sign of an electrical short that needs to be rectified right away. If your car is having multiple electrical issues, there may be a significant problem that requires diagnosis by an expert.

Frequently Asked Questions

How To Tell If A Fuse Is Blown

Take the fuse out of the holder. You may need to occasionally unscrew the fuse holder cap with a small screwdriver. Check the fuse wire. You will need to replace the fuse needs to be replaced if there’s a clear space within the fuse or if there is a dark or metallic stain in the glass.

What Does A Blown Fuse Look Like

While a glass fuse’s element may be easily visually inspected to determine whether it has blown, most fuses have solid, opaque bodies that conceal the element from view. We need to use a multimeter to determine whether the fuse is blown. Once set up, a multimeter can gauge the fuse element’s resistance.

What Does A Fuse Do

If an appliance malfunction results in an excessive current flow, the fuse shuts off the circuit. In case something goes terribly wrong, this will safeguard both the wiring and the appliance. There is a wire inside the fuse that melts easily.

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