Tuesday, September 27, 2022

How To Check Car Fuses

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Where Fuses Are Located

How to check car fuses without pulling them out – Testing fuses with a Multimeter

On most every car, you’ll find a primary fuse box under the hood. On modern cars, it’s usually a plastic case with a protective cover. To access the fuses inside, just remove the cover. On the inside of the cover or in your owner’s manual, you’ll find a diagram that tells you what each fuse is connected to and what amperage each fuse should be rated for.

You might also find secondary fuse boxes in the interior. Commonly, you may find a fuse box behind a dashboard trim piece near the driver’s footwell, but they can also be located in the trunk or under the seats on some vehicles. Check your owner’s manual to be sure.

Electrically Testing A Fuse Without Removing It

If you don’t want to break electrical continuity to components a fuse handles by pulling it out, a fuse can be checked while still in place using a voltmeter or a multimeter set to “V” . Note! Do NOT use a multimeter set to “Ohms” to test an electrically live circuit! With the ignition switch in the ON position, touch or clamp the black test lead to a good known ground.

On the end cap of a blade fuse, you’ll see two exposed areas of metal designed for testing. Touch the red test lead to the first metal square, then to the other. You should see a voltage reading in the 12-14 volts range. Readings on both sides of the fuse indicate it is working properly. If the fuse is good but the device controlled by the fuse does not function, then there is a problem somewhere downstream of the fuse. If only one side of the fuse generates a voltage reading, the fuse is bad. If neither side yields a reading, there is no current flowing into the fuse to begin with – indicating an electrical problem upstream of where the fuse is.

What You Will Need

  • Turn off the ignition and disconnect the negative terminal.

  • Locate the fuse panels. Most cars have two to three fuse boxes. The main fuse box is typically in the bay. Your vehicle will also have an interior fuse panel. Typically under the dash or on the side of the . It may also be behind the glove box, below the rear seat, or in the trunk.

  • Remove each fuse one by one and inspect it to determine if the fuse is blown. A blown fuse will have a broken wire in the middle and most likely will be black. Left – Good Fuse Right– Blown Fuse
  • If you are looking for a specific fuse, look at the fuse chart and identify the location of the system in question. The fuse chart is usually printed on the back of the fuse box cover, it may be a letter inserted in the fuse box, or some car manufacturers will include the fuse chart in the owner’s manual.
  • Replace bad fuse. Once you identify the bad fuse, you need to replace it. Always replace fuses with the same ampere rating. The ampere rating is printed on the fuse and is also shown in the fuse chart. Don’t install a fuse that has a higher ampere rating. This can lead to damage of electronic components in your vehicle and possibly even fires in some cases.

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    Test Fuses With Your Circuit Tester To Find Constant Fuses

    Now its time to test the fuses. Probe the fuse by touching the tip of the circuit tester to the exposed metal prongs on both sides of a fuses face. Since the engine is off and the key is out of the ignition, you should be able to probe the fuses and determine which are constant. The constant fuses are the fuses that light up your circuit tester.

    If you find a combination of both constant and switched fuses in your fuse box great! Were on track. If you find only one type of circuit in your fuse box, dont fret. Some vehicles may require additional testing, and well cover that later on in this tutorial.

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    How to Test Car Fuses with a Multimeter

    Its not in every case simple to fix the needles yourself in case youre suspicious with regards to the issue. In any case, start with the most over-the-top heinous causes, If a hand doesnt work. Look at the circuits, the bulbs, and the introduction for potential causes and results. A few issues might appear in individual abstracts, so you may have further karma in the event that you plug the treasury into the autos novel connection and take a look at the standards. It can habitually lead you the correct way.

    Else, you should take your auto to the shop and have an expert glance at the issue. Notwithstanding, you might end up pulled over for speeding or sitting out and about without any gas If your speedometer isnt working right or the energy hand quits working.

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    Why Do Fuses Blow

    Weve mentioned that fuses sometimes blow and that some fuses are more prone to this than others, but we havent discussed what causes this to happen, so lets have a look.

    A blown fuse is caused by a short circuit within an electrical circuit. In most cases, this short-circuiting is caused by two wires connecting when they are not supposed to, or one of the power wires in the circuit coming into contact with the metal body of the vehicle.

    As well as these possible causes, short-circuiting can also be caused by a car part drawing more electricity than it is designed for, so issues with motors in your vehicle can also cause fuses to blow.

    But these arent the only things that can cause a fuse to blow. Sometimes it can be something as simple as a metal coin coming into contact with one of the vehicles power sockets to cause it to blow. It can also be caused by an incompatible headlight being fitted, so there are lots of possible causes of fuses blowing.

    A lot of people assume that the first thing that you should do after a fuse blows is replace it, but this isnt the case. If you replace a blown fuse but dont fix the route problem of it then this can cause the replacement fuse to blow as well.

    So you should identify the cause of the blown fuse before you do anything else.

    Electrically Testing A Fuse That Has Been Removed

    Testing a fuse out of the vehicle can be done with a multimeter set to “Ohms” or continuity. Touch the red lead to one metal end of the fuse and touch the black lead to the other metal end of the fuse. If the fuse is fine, the multimeter will show a resistance reading of zero , or “continuity”. A blown fuse will result in no reading, also known as an “open circuit”.

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    Why Dash Gauges And Lights Dont Work

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    How To Check Car Fuses With A Multimeter-Tutorial To Check If A Fuse Is Good

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    How To Test Fuse

    The first step before testing a fuse with an automotive multimeter is making sure that the car is off and the keys are not in the ignition. You can read this article to find one. This will help keep you safe when pulling the fuse out and also protects the car. The next step is to locate the potential bad fuse. To do this, you go to the fuse box and look at the diagram or in the owners manual and find the one that corresponds to the system you are having trouble with.

    For example, if your power door locks aren’t working, then you will want to pull the fuse that goes with that. Then to pull the fuse, you do literally what it is called, and that is pulled straight up on the fuse. You want to make sure you pull straight up because you don’t want the prongs getting bent or damaged as you pull the fuse out.

    Once you got the fuse pulled you can visually inspect it. If it is clear plastic you can try to see if the connection seems broken. If you can’t see the wire through, then it is time to get the multimeter out. To use the multimeter you first have to turn it on and get the probes out. You then can set the multimeter to ohms.

    This will measure the resistance of the fuse. You can then touch the probes together. This gives you a baseline reading and will tell you roughly the number you will get once you put the probes on the fuse. Once you have an idea of the reading, you should expect you can connect the probes to the fuse.

    How Can You Tell If A Fuse Is Blown In Your Car

    a blown fuse can be indicated by a reduced or non-existent performace of an electrical system.

    the first thing you should do is check the fuses to make sure they have not been replaced with another type of fuse, blown out, disconnected from the vehicle wiring, or pushed back into the fuse box. these events could indicate how and why your car’s power systems are malfunctioning.signs that a fuse has blown might be found in any one of these four specific areas: brake lights not functioning air conditioning running intermittently windshield wipers stop working after turning off engine and electric doors stop working when turning off engine and pulling up on door handle . automobiles typically blow f

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    How To Check For A Blown Fuse

    If a certain electronic component on your car has suddenly stopped working, try checking the fuse yourself! Some cars come with a fuse puller that can be stored in the fuse box, but if you’ve misplaced yours, just grab an ordinary pair of tweezers or needle-nose pliers. Use your owner’s manual or fuse box diagram to find the fuse associated with the malfunctioning component. Just grab the fuse with your tweezers and pull. If the metal filament inside is still in-tact and in one piece, the fuse has not blown. That means there could be something wrong with the malfunctioning component itself. However, if the fuse has melted and a gap has formed inside the fuse, the circuit is incomplete. To restore the circuit, you’ll need to replace the blown fuse with a new fuse of identical size and amperage.

    How To Inspect Car Fuses

    HOW to check and replace blown car fuse

    Rocco Lovetere

    A fuse is a low-resistance resistor device that protects a circuit from becoming overloaded. It is a short piece of wire that is designed to melt and break apart when exposed to an excess of electrical current. A fuse is connected in series to the circuit it protects.

    A blown fuse usually causes an electrical short or an overloaded circuit. The most common fuse to burn out in a car is the 12v power outlet, also known as the cigarette lighter. This is often caused by leaving a cell phone charger in it for a long time, or because of the occasional stray penny that falls into an exposed power outlet.

    A fuse box is located in the car and houses the fuses. Some cars have multiple fuse boxes with many different fuses. If something electrical in your vehicle suddenly stops working, start by checking the fuse box and get a certified mechanic to take a look and diagnose any electrical problems.

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    Test #3 Continuity Tester

    There are many different types of circuit testers out there. Continuity Tester is another easy way to check your fuses for problems. It is a low-cost alternative to multimeters and this is how you use it:

    • Step 1. By pressing the metal probe to the corresponding clip on your continuity tester, you can make sure its operating. It should light up if its working.
    • Step 2. To test a fuse, simply contact the probe and clips to the end of the fuse, as you would with a multimeter. The fuse is operating if the tester lights up.

    ** Important! Before testing, make sure there is NO electricity flowing through the fuse.

    Here are some continuity testers that I found for you :

    This is how you use this continuity tool to check fuses:

    How To Test A Car Fuse Using Multimeter Continuity Mode

    In this method, you are going to learn how to test a car fuse using multimeter continuity mode.

    Below is the step-by-step procedure of testing the car fuse with multimeter.

    Step 1. Remove The Fuse From Circuit

    First, remove the fuse from the suspected circuit.

    Step 2. Select The Continuity Scale On Multimeter

    Turn the selector to continuity scale or radio wave symbol on the multimeter and have a quick test to prove the multimeter is good by touching both leads together to hear a beep sound.

    Step 3. Connect The leads To Fuse

    Place the fuse on a non-conducting material and connect the tips of the black and red leads with both terminals of the fuse.

    This is an InfoWhile testing a car fuse, you can connect either lead with either terminal of the fuse. They are polarity-free .

    Step 4. Read The Multimeter Display

    If it beeps, the fuse is good.

    If it isnt, the fuse is bad.

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    Visibly Inspecting A Fuse

    Using the owner’s manual, locate where the fuses are. If you don’t have an owner’s manual, a quick internet search or call to the manufacturer should produce the information. On many vehicles, fuses may be lined up behind a panel under the dash or on a side of the dash obscured by the driver’s door when closed.

    On other makes and models, fuses may be contained in a box under the hood. Fuse panels and fuse boxes have a cover piece that may require a small flathead screwdriver to remove. On the back of the cover piece, you’ll find a diagram which shows you the position of each fuse so you can locate the one you need to check.

    Whatever their design, fuses will be clearly labeled with their ampere ratings. Physically remove the fuse using a small, specially shaped fuse puller tool. The tool serves to clamp around the numbered outer edge of the fuse that you can see. Some automakers include this tool within the fuse box.

    Once you’ve got a grip on the fuse, wiggle it out by pulling gently toward you in the same fashion you’d pull a tooth. If you don’t have a fuse-pulling tool, a pair of needle-nose pliers will provide needed grip and maneuverability. Use caution to ensure you do not “short” the metal part of the pliers against a live circuit.

    How Do You Replace An Automotive Fuse

    How to Test Car Fuses Using a Test Light

    Replacing an automotive fuse is one of the easiest automotive repairs you can do. Some fuses can simply be pulled out by hand, while others might require a fuse puller because theyre in tight spaces.

    • Modern blade-type fuses are very common, such as APM, APR, ATC, ATO, ATS and APX, and can be removed with a fuse puller, usually close by in the fuse box.
    • Older glass-tube type and Bosch type fuses are round and can be removed with a fuse puller designed for them.
    • Needle-nose pliers can be used, but carefully, as you could inadvertently cause a short circuit, which is why fuse pullers are made of non-conducting plastic.

    After removing the burnt-out automotive fuse, match it up with a new fuse and install it. Be sure it matches both size and amperage rating, or else it either wont fit or might cause damage. Dont use non-fuse items, such as foil, paper clips, or jumper wires, in place of a proper automotive fuse. Using a lower-rated fuse, such as a 5 A instead of 10 A, may work, but might blow under normal load. Using a higher-rated fuse, such as a 15 A instead of a 10 A, will work, but may not sufficiently protect the wiring in case of overloading. If your fuses keep blowing, you have an electrical problem that requires further investigation.

    If you have questions about this story, please contact us at

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    What Does An Car Fuse Do

    An automotive fuse is an overload safety device. Under normal circumstances, a certain automotive circuit might carry 5 A ampere is a measurement of electrical current while in use. Under certain circumstances, that current varies, so wire gauge is chosen at two or three times the expected load.

    In case of overloading, such as a stuck electrical motor or short-circuit, the current in an unprotected circuit would go far beyond the capabilities of the wire to carry it. Theoretically, Ohms Law tells us a short-circuit would allow infinite current through our 15 A wire. The overloaded wire would overheat, melting the insulation, possibly the wire itself, as well as possibly melt or ignite surrounding wires or materials.

    To prevent such damage from occurring, an automotive fuse is placed in the circuit. The fuse might be rated two times the expected load to allow for fluctuations during use. If something like an overload or short circuit occurs, the softer metal in the fuse overheats and melts, cutting off the rest of the circuit from current. This protects the wire from meltdown and prevents damage and fire in areas surrounding it. Of course, this prevents that circuit from operating again, until the fuse is replaced.

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