How to check continuity in a long wire

How to Check Continuity in a Long Wire?

While you are trying to work on some DIY projects one of the annoying situations we hate to get into, is to keep doing the same thing over and over again.  

Imagine trying to run an extra light outside your house, or you are trying to light up your garden as you set up that nice date with your special someone, everything you have done seems right except that the lights wouldn’t come on. You may have a lot of suspicions, but have you checked your wires?

We trust our electrical stores but these wires may have been roughly packed, and due to that they break. A broken wire wouldn’t have continuity; continuity is creating a path for current to flow through. 

The wires we buy for our DIY projects are so long we don’t know if they are broken or not, so how do we check for continuity in long wires?

electrical wires

How to check continuity in a long wire

  • Understand the basics
  • Continuity test
  • Preparing your multimeter
  • Carry out the test

Read more detailed info on each step below: 

Understand the basics

Most times, what we often do is to attack a problem without understanding them. Now that we have briefly described continuity in wires; now we would go in a few other basic knowledge.

Your electric wires are conductors of electricity; they are also resistors. One thing you should know about wires is that their resistivity varies, it may depend on the type of the wire, the thickness or the length of the wire.

Currents move through the wires as electrons flow through them, but as they collide with ions in the conductor, resistance is formed. In the case of long wires, there is more resistance because electrons and ions collide more often.

Continuity test

Carrying out the check of continuity in a long wire is one of the easiest electrical tests you can perform, but before testing, the first thing you should do is to turn off the power supplying the wire you are working on, it is an important safety tip you shouldn’t ignore.

You would need a device called the multimeter, with a multimeter you can test for current, voltage and resistance in your wires, circuits, switches, electrical connections or components, appliances or other conductors.

Continuity is a test you carry on your wire, using a multimeter to detect the resistance of the wire. It proves the path of a complete flow of current through your wire.

Preparing your multimeter

Now with your multimeter (for this test we use Fluke 115, which you can below ), to test for continuity, turn the dial to ohms settings. The multimeter would display “1” or an “OL,” meaning “Open Loop” which is the highest scale of measurement.

The multimeter at this point practically measures the resistance of air between your two leads which is more than it can count.

Some multimeter may require that you press the continuity button. Your multimeter would have two wires, each with ballpoint pen ends, a red which is the positive wire and a black which is negative.

Now, connect your probe wires to your multimeter by inserting the black test lead into the COM jack and the red test lead into the V Ω jack, make sure they are appropriately jammed in.

Carry out the test

To carry out the check on your long wire set your multimeter to 200 ohms. You should note that the range you set would determine the resistance of the components you are testing. Lower ranges should be set when you are testing components of low resistance, while high ranges should be for testing higher resistance. For determining continuity in long wires, 200 ohms is appropriate. 

We recommend that the next thing you should do is perform a test on the resistivity between your two probes by placing the probes together you may begin to get a reading of approximately 3 ohms or a figure close to that, this proves that continuity exists between the probes. 

With that done, don’t forget to ensure the circuit supplying electricity to the wire is switched off, not only that, you may also need to remove all other components connected to it, like your bulb sockets or switches.

Then take out your long wire, connect your probes to each end of it (the order of placement doesn’t matter), you should begin to get a reading of approximately 3 ohms.

But then again, your readings should be as low as possible, to proves that continuity exists in your long wire, the circuit is complete, and the switch is closed.

When you placed them accordingly, and your multimeter still reads “1,” then you may have a break in the wire. So consider getting another long wire.


We have fully explained how you can check for continuity in a long wire.

A quick reminder on the test process:

  • Turn off your electrical power supply.
  • Set your multimeter to measure ohms and set the range.
  • Connect your multimeter probes to each end of the wires.
  • Check your reading.

If you are carrying out your continuity test with a digital multimeter then you might not need to see the reading before you detect continuity, because immediately continuity is detected in your long wire, your multimeter would beep.

It would only not beep if your circuit is open and there is a damage in your wire.

After your test, you can unassemble your multimeter, but this time remove the leads in reverse order as you have assembled them. Remove the red probe first and then the black, and properly pack them.

If you don’t use an auto power multimeter, ensure to turn it off, so you preserve the battery life.

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