How to Test Cable Continuity with a Multimeter

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To test cable continuity with a multimeter, disconnect the cable from any live circuit, set the meter to continuity mode, and touch one probe to one end of a conductor and the other probe to the far end. A tone, or a reading near zero ohms, means that conductor is continuous. An open reading means the conductor is broken somewhere along its length. Repeat for each conductor, and check that no two conductors are touching each other. The three sources we opened describe the same basic method, with different levels of detail.

Quick answer

• Make sure the cable is disconnected from any live circuit and from any device at both ends.
• Set the meter to continuity mode, marked with a diode or sound-wave symbol.
• Touch the probes to the two ends of one conductor. A tone means it is continuous. No tone means it is open.
• Test each conductor on its own. A tone between two conductors that should be separate points to a short.

The person typing this wants to know

The person typing this phrase has a cable that is not carrying a signal or power, or a cable run they need to confirm before they connect equipment. They want a method they can do with a basic multimeter, and they want to know what a missing beep means for the cable. This guide covers general cable testing on a disconnected cable. It does not cover live wiring or building circuits.

How we chose

We opened three sources and read each one. The iFixit guide, How to perform a continuity test, is short and gives the setup and the audible mode. The SparkFun tutorial on continuity mode is a general explainer that covers probe placement, the tone, and the de-energize rule. The Docsie tutorial, Check continuity with a multimeter, gives the setup, the end-to-end test, and the reading for an open path. We did not use search snippets, and we did not use any store or product page. We kept only the steps that the sources state directly.

Step 1: de-energize the cable

Disconnect the cable at both ends before you test it. The SparkFun tutorial says to test only parts that are disconnected from any live circuit, and it warns that testing high-voltage or powered circuits can damage the meter or cause injury. The Docsie tutorial makes the same point. Turn off the equipment, unplug it, and confirm nothing is powering the cable before you touch the probes.

If the cable runs inside a wall or ceiling, or it is part of fixed building wiring, stop here. Lock out the circuit at the panel, confirm it is dead with a rated voltage tester, and get a licensed electrician involved. A multimeter continuity test is not a substitute for that check.

Step 2: set the meter

Plug the black lead into the common jack and the red lead into the jack used for resistance and continuity. The Docsie tutorial describes this setup, and it tells you to power on the meter and turn the dial to the continuity setting. Then check the meter. With the leads apart it should show an open reading, usually shown as 1 on many meters. Touch the tips together, and it should read near zero and give a tone.

The SparkFun tutorial describes the same mode, a diode symbol with waves beside it, and says the meter should give a tone when the probes touch. Our sources agree on the mode, although they name the jacks and the displayed open reading a little differently. Check your own meter’s manual, because the open-reading symbol differs between models.

Step 3: test one conductor from end to end

Hold one lead at one end of a conductor and the other lead at the opposite end. The Docsie tutorial says a reading near zero means the conductor is continuous, and a reading that stays at 1 means it is open. The SparkFun tutorial says a beep means the path is intact and silence means there is a break. Both describe the same result.

If the cable is long or hard to follow, the SparkFun tutorial suggests you can probe along the route to find where the break is. That method works when you can reach the conductor at more than one point. It does not tell you the break location on a cable you cannot access.

Step 4: check each conductor on its own

Test each conductor one at a time, and record which ones pass. A multi-conductor cable needs each conductor checked, not just one. The SparkFun method applies to each conductor in turn: one probe at each end of the same conductor, then move to the next. The iFixit continuity guide we opened is short and does not describe a multi-conductor procedure, so we do not attribute one to it.

When a conductor fails, you have two possibilities. It may be open, which means a break in the conductor, or the connection at one end may be loose or dirty. Check the connection at both ends before you decide the conductor is broken.

Step 5: check for shorts between conductors

Continuity testing also looks for unintended paths between conductors. Touch the probes between two conductors that should be separate. A tone or a near-zero reading means they are touching somewhere along the cable. The sources we read do not give a full procedure for this on a multi-conductor cable, so treat this step as a check that you can perform with care, and confirm it against the cable maker’s documentation.

If you find a short, stop using the cable. The sources we read do not describe a repair, and a cable with an internal short should be replaced rather than patched.

Reading the results

• A tone or a reading near zero on a conductor: the conductor is continuous.
• A reading that stays open: the conductor is broken or the connection is bad.
• A tone between conductors that should be separate: a short between them.

A single open reading does not tell you which part of the cable has failed. Test the connectors and the terminations first, and then the cable run itself.

Safety notes

• Test only disconnected cable. Do not probe a cable that is connected to a powered device or outlet.
• Do not test cable inside a wall or ceiling without locking out the circuit and confirming it is dead.
• Use a meter whose probes and leads are in good condition, and do not use a meter with damaged leads.
• For building wiring, a licensed electrician should decide whether the cable is safe to re-energize.

What a continuity test does not show

A continuity test checks for an electrical path. It does not check whether the cable carries a signal at the speed or quality the equipment needs, and it does not check insulation. A cable can show continuity and still fail under load or when flexed. The sources we read do not describe an insulation test, so this article does not describe one.

If you want a broader view of what continuity mode can and cannot show, our article on continuity testers covers how these tools are used and where they fall short. For a related case on outlets, see our article on GFCI open ground.

What we could not verify

• The iFixit guide is short and does not explain how to find a break along a long run. We did not verify a break-location method from that source.
• The sources do not give a numeric limit for what counts as continuous on every cable type. The article does not state one.
• We did not verify a method for testing shields or coaxial cable from the sources we read.
• The sources do not describe signal integrity or insulation resistance, so this article does not claim either.
• The Docsie and SparkFun tutorials are general electronics and field-service guides. They do not cover a specific cable type, so the steps here are general.

FAQ

Do I need to disconnect a cable before a continuity test?

Yes. The SparkFun and Docsie tutorials both say to test only parts that are disconnected from any live circuit. Testing a powered circuit can damage the meter.

What does an open reading on a cable mean?

An open reading means the meter does not find a low-resistance path between the two probes. On a conductor, that points to a break or a bad connection.

How do I find where a cable is broken?

The SparkFun tutorial suggests probing along the route where you can reach the conductor at more than one point. If you cannot reach the conductor, the sources do not describe another method.

Can a continuity test show that a cable is good for high-speed data?

No. A continuity test checks for an electrical path only. It does not check signal quality or speed.

Should I repair a cable that fails?

The sources we read do not describe a safe repair. We do not give one.

Bottom line

De-energize and disconnect the cable, set the meter to continuity, and test each conductor from end to end. A missing tone means a break, and a tone between conductors means a short. Replace the cable rather than trying to patch it.

Sources

• iFixit, How to perform a continuity test: https://www.ifixit.com/Guide/How+to+perform+a+continuity+test/150264 (opened 2026-10-30)
• SparkFun, RETIRED – How to Use a Multimeter, Continuity: https://learn.sparkfun.com/tutorials/retired—how-to-use-a-multimeter-/continuity (opened 2026-10-30)
• Docsie, Check continuity with a multimeter: https://www.docsie.io/tutorials/field-service/check-continuity-with-a-multimeter/ (opened 2026-10-30)