How to Test for Continuity

When voltage is not flowing through a circuit properly, there can be a number of reasons for the problem. There can be a break in the line, a loose connection or some other problem like a blown resistor. A continuity test will tell you whether or not there is a problem between points A and B on a given circuit. Here is how to test for continuity.

Things You'll Need

• Multitester

Instructions

1. Turn the power OFF to the circuit of whatever it is you are testing before performing the test. This is extremely important.

2. On your multimeter you will notice a bunch of different settings. You are going to want to set your tester to read ohms. This is the symbol that looks like an "O" with feet, or more commonly known as the Greek Omega symbol. If your multitester features numerous settings under the ohms symbol, just set it to X1.

3. If you look at your tester when the probes are not touching anything, you should see a reading of infinity or OL. Touch the two probe tips together and you should see the reading change to zero. If your tester features an audio alert, it too will sound as you touch the probes together.

4. Now what you are going to want to do is touch one probe tip to one end of the resistor and the other probe tip to the other end of the resistor. If the circuit is "closed," the tester will read zero and you should hear the audio beep if it has that feature. If the circuit is "open," the tester's reading will not change.

5. Here is a clarification on what an "open" or "closed" circuit means:

   Open circuit: When the circuit is not complete, meaning that no voltage is able to flow through. This can be caused by a blown fuse, resistor or a switch.

   Closed circuit: When the circuit is complete, meaning that voltage is able to flow through it.

   You can perform a simple continuity test on a light switch that is not wired to anything. With the switch off, probe the terminals. You should not get a reading on your tester. But, when you turn the switch on, you will notice that the tester will read zero and the beep should be heard, signaling that the circuit is closed or complete.

Tips & Warnings

• Always make sure the power is OFF to whatever you are testing for continuity. If not, you could damage the equipment and your multitester.

Resources

• Read this Article in Spanish
• How to Use a Multimeter
• How to Measure Electrical Resistance
• How to Test for Ground