Continuity Test with Multimeter: Why You Should Use It to Confirm Complete Circuits

There’s a variety of tests to do to confirm your electrical setup works right. These checks are imperative because you want to maintain the system in good shape. Furthermore, you want to minimize health risks and other potential issues. A continuity test is an essential part of checking if a component or device works well. You can do a continuity test with multimeter instruments, and here is a detailed guide on why and how to do this check!

Continuity Test – An Overview

Whether you have an automotive wiring harness or a different setup, you want a working electronic system. You can confirm a circuit works right by checking if the current goes through it. That’s what a continuity test means – it will ensure that a circuit is complete.

The continuity test is simple, and it involves sending a small voltage through the desired direction. The flow should go through that path to confirm the circuit is complete. But if there’s too much resistance, it means there’s a problem. It could be component damage or a broken conductor, but it indicates an “open” circuit. That’s a problem you should deal with as soon as possible. Continuity tests serve to discover them on time and avoid further issues.

When Can You Use a Continuity Test?

An electrician checking a fuse box

Caption: An electrician checking a fuse box

Here are some examples of what you can test for continuity:

  • Fuses
  • Switches
  • Wires
  • Conductors

You can check any electrical connections for continuity. If there’s a bundle of wires, it can also help to find a particular one. You can test until you note some resistance, which indicates you found the same wire.

Multimeter – An Overview

It is a versatile electrical instrument you probably have around if you are a DIY enthusiast. A multimeter is the easiest option to test continuity, and it can also measure resistance, current, and voltage. A digital multimeter has a screen where you can ready the results. 

The device can test DC and AC current and measure small and big currents, voltages, or resistance. A modern digital multimeter with connection terminals can also measure frequency, temperature, capacitance, etc.

The Working Process of a Multimeter

A mechanic checking battery car voltage

Caption: A mechanic checking battery car voltage

According to Ohm’s Law, you divide voltage with resistance to get current. It is something that battery-operated multimeters use, and they find two quantities and use the equation to identify the third.

A multimeter with a connection measures current, voltage, and resistance. If you want resistance, it will measure how the current changes voltage, and it’s the primary use of Ohm’s law.

Steps to Using a Multimeter for the Continuity Test

Testing voltage with a multimeter

Caption: Testing voltage with a multimeter

It’s simple to test continuity with a multimeter, and it only takes joining the device’s terminals to the electrical connections’ ends. However, you still want to do everything right. If you are having any dilemmas, these are the steps to follow while testing!

Preparing the Multimeter

First, you need to prepare the device. You’ll begin by adding multimeter connections. Use the red and black cables and insert them into their spots. The black cord goes into the “COM,” which is the ground. On the other hand, the red cord will measure voltage, amperage, or resistance. You should only use the “10Amax” field if you want to measure high currents. Each cord has a terminal, which is its visible metal part. This part serves for measurement, and that’s why it’s a crucial component.

Which Setting to Choose?

The next task is to pick the continuity mode on your multimeter. The symbol will vary on the device, but it commonly has a diode. If you can’t find a diode, consider consulting the manual to discover which symbol your multimeter uses.

Please note that some devices don’t come with a continuity option. If that happens, check the resistance modes available. Next, find the lowest option and pick it. If you are unsure, consult the instructions since they might explain how to enter the desired mode.

Now, grab the red and black cord for the cable. Test the terminals by making them touch together. Next, hold that position and read the result on display. If the value is below “1,” you can proceed with the test. Some devices will even note that everything works well with a sound signal. 

If you get a higher reading, check the adjustments. It can help to try other terminals or consult a manual for other error solutions.

Test the Signal

An electrician testing the fuse box with a multimeter

Caption: An electrician testing the fuse box with a multimeter

First, here is a crucial safety tip – turn off the device you are testing. And don’t just deactivate it, but unplug it from the power socket. You won’t get a proper reading otherwise. The test involves sending a small current and checking the resistance. If you get more current, the reading won’t be correct. Furthermore, it can be a health hazard, so unplug the device first. 

Another tip is to wait for about 60 minutes after unplugging the appliance, and that’s because it takes time for the device to de-charge. Once you turn off the appliance, you can test all its fuses and wires.

Details about the Testing Process

First, take the black and cords of the multimeter. Here is where to place them:

  • If testing a fuse, put the black terminal anywhere on the metal conductor, and the red one should go on the body. However, make sure that they don’t touch to ensure an accurate reading.
  • For wires, put the terminal on the visible wire’s end. The red terminal should go against the wire when testing it for safety.
  • If you test soldering, anywhere on the material will do. However, make sure that the red and black terminals are on the opposite ends.

The metal part must keep touching the material. Now, wait for a couple of seconds, and the result on display will stabilize. During the process, make sure to hold the red and black cords as still as you can.

What Do the Results Mean?

An electrician checking socket voltage

Caption: An electrician checking socket voltage

You’ll now have the results, but it’s essential to figure out what they mean. The general rule is that you should aim for the “0.” If the zero shows constantly, that’s an ideal connection. The same applies to devices, fuses, and wires.

The good news is that your connection is safe as long as the reading is less than “1.” The usual reason why you get a reading higher than zero is that you use dirty terminals. You can try turning the device off and wiping the edges thoroughly. If you test the device again, you might notice a lower result. But as long as the reading is under “1,” the circuit is safe.

So, what happens if the reading is higher? That can be normal for some devices, so check the instructions first. Some systems have acceptable resistance up to “10.” However, make sure that the manual or a professional confirms this.

The problem occurs when the reading is above “10.” It indicates poor continuity, which means you should replace the component. Otherwise, you are dealing with potential safety problems. Make sure the entire wiring system is optimal and suits your application.

What if you get no reading? First, check if the multimeter works right. Next, clean the terminals and measure again. If you don’t get a reading, that means something is wrong with the wire.

Important Notes for Doing the Continuity Test

  • Make sure to unplug the device first. The component you are testing shouldn’t have any charge. That way, you’ll ensure correct readings.
  • If you are testing continuity, it doesn’t have a specific direction. You can switch the terminals, and the results won’t change.
  • Inductors and small resistors might look like a short circuit to your testing device. It’s essential to know the difference between a high-drain and short circuit.

Conclusion

It’s easy to do a continuity test with a digital multimeter. However, make sure to stick to safety tips. If the check discovers a problem and you need new wires, contact Cloom today. Our experts are ready to help deliver premium equipment for any electrical setup!

Hey, I am John, General manager of Cloom and OurPCB.

I am a responsible, intelligent and experienced business professional with an extensive background in the electronics industry.

Reach me at sales@wiringo.com to get a quote for your projects.

Lets Cloom Suport Your Projects

Get A QUICK QUOTE

Fill in your details and we’ll get back to you in 24 Hours.

Get A QUICK QUOTE

Fill in your details and we’ll get back to you in 24 Hours.