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How To Test Automotive Circuit Breaker In 5 Easy Steps

Suppose, you are preparing to go out in your car and suddenly discover that the headlights don’t work. It may put you under a lot of pressure as replacing headlights is not cheap at all. But little do you know, it can be the circuit breaker of your car that has gone bad.

How to test an automotive circuit breaker?

First, you need to find the fuse box located under the driver’s dashboard. Getting to the fuse box, remove the circuit breaker that you want to test. Connect the probes of a voltmeter to the circuit board. If there is a reading on the display, the circuit is okay and the circuit breaker has gone bad.

Do you like what you have read? If you want a detailed discussion on this particular topic then we have just the right thing ready for you. Read our dedicated segment on this below!

Testing Automotive Circuit Breaker

Testing the circuit breaker installed in your vehicle is pretty straightforward. It is quite similar to electric circuit breakers. The only hassle in this process is to get to the fuse box. Otherwise, it’s nothing but a simple voltage check procedure.

If you follow along with the process, next time you won’t need a mechanic to check your car to verify if the circuit breaker is okay or not. With only a few minutes in hand and the necessary tools, you can easily check your vehicle circuit breaker with ease.

Things You Would Require

You don’t need fancy power tools to check your automotive circuit breaker. All the things you would need can be found very easily in your garage. These are what you would require:

  • A multimeter/voltmeter
  • A screwdriver 
  • Some wires

Now, if you have these tools in hand, let’s discuss how to test your vehicle circuit breaker:

Step 1: Turn Off the Car

It is absolutely instrumental to turn your car off before you start messing around with it. Keeping the car turned on while trying to reach out to check the circuit breaker is extremely risky.

Please remember to switch your car off and give it a rest for a few minutes for everything to cool down. Then start reaching for the circuit breaker.

Step 2: Locate the Fuse Box

The fuse box is where the circuit board of the car is placed. In that circuit board, a circuit breaker is installed to keep the vehicle protected from uncertain situations. Circuit breakers work similar to a surge protector that can go bad.

In most cars, the fuse box can be accessed from underneath the driver’s dashboard. For this step, you will need your trusted friend, a screwdriver. Open up underneath the dashboard and look for the fuse box.

There will be a lot of wires and connections underneath there. Be very careful while you are doing so. Don’t rush as these wires are quite important. There would be different panels and dashboard trim on your way too. Keep these safe.

Step 3: Remove the Circuit Breaker

When you have reached the fuse box, open it up. Remove the circuit breaker that you wanted to test and keep it aside. You are now presented with just the circuit board. It is basically the power control hub of the vehicle.

After removing the circuit breaker, turn the car on. Now, the car can push power through the circuit board and you need to check if the voltage is alright or not.

Step 4: Connect a Multimeter/Voltmeter to the Board

Now that you reached the circuit board, identify the hot/positive terminal as well as the cold/negative terminal. You would need to attach the probes of the multimeter to those terminals accordingly. Turn the DCV mode on for the multimeter.

You don’t need to do any changes if you are working with a voltmeter. Connect the red probe to the hot terminal and the black probe to the cold terminal. With the vehicle turned on try to get the voltage reading on display.

Step 5: Read the Voltage

After connecting the voltmeter, see the display for voltage measurements. If it is a digital meter then the voltage will be written on display in a numerical form. If it is an analog meter, then there will be an indicator point at the positive-negative reading.

If the meter picks up the voltage, then the problem lies within the circuit breaker and it needs to be reset or replaced. But if there’s no or low reading on the meter, then there’s no or low voltage running through the circuit board.

That indicates, there are faults in the board or some wiring issues. If this is the case, then visit a mechanic at your service center. They will try to identify the issue and fix it.

A good circuit breaker is essential for keeping your vehicle. Check out our top pick for this segment:

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How Does An Automotive Circuit Breaker Work?

An automotive circuit breaker is the same thing as a normal circuit breaker, however, installed in your vehicle. It protects your vehicle from physical damage when necessary by cutting off the power supply to the components.

While your car is on, if the circuit breaker detects any irregularities such as a sudden rise in temperature or current overflow, it stops the power supply. A circuit breaker is installed on the circuit board that can be found in the fuse box of the vehicle.

If you face strange issues like stereos not working or headlights not turning on, you should probably check if the circuit breaker is tripped or not. Such incidents are very common and need only about 15-20 mins to fix at maximum.


Question: How do I know if the circuit breaker is tripped?

Answer: If the voltage reading is perfect while checking the circuit board, then it’s highly likely that your automotive circuit breaker has tripped. Try resetting or replacing it. 

Question: How to reset the circuit breaker?

Answer: Identify the circuit breaker. You will see a button at the center of the breaker and that will be popped out. You just need to press that into its place.

Question: How Do I check the amps on a circuit breaker?

Answer: To check the amps on a circuit breaker, you can connect it to a multimeter. It shows you the reading on how much amps are being drawn.

Wrap Up

Thanks for putting up till the end. We hope this article has provided you with enough information on how to test automotive circuit breakers. For expert advice, always visit the service center.

Best of luck!