Have you ever woken up in the middle of the night only to find pitch-black darkness? You try to go back to sleep, but you’ve watched too many horror films for that to happen. So what do you do? You lazily extend your arm, trying to adjust the plug of your night lamp into the socket. But that doesn’t work. Let’s find out how you can test a plug socket with a multimeter.
But before that, you must know how to use a multimeter or at least a basic idea of this subject along with the safety concerns about the equipment that you are using.

Testing a plug socket with a multimeter:


  • It is best to hold both the probes in the same hand so that the shock does not pass through your whole body. Make sure that the metallic portion of both probes does not touch each other because that may cause a serious short circuit. The electrical outlet must be present.
  • Now set the multimeter to measure voltage. You may do this by rotating the dial so that it points to the Voltage symbol. Make sure that you’re selecting AC (alternating current) and not DC since we’re going to be measuring AC (alternating current) voltage. The AC voltage symbol will have a wavy line, while the DC voltage is represented by a straight line.
  • Make the connections. Insert the black lead in the input jack labeled COM (for communal). At the same time, the other lead goes into the jack with an ohm symbol (Ω) beside it. The electrical outlet should work fine.
  • Now insert the probe into the slots of the socket. The red one goes in the shorter slot, which is usually the right one. At the same time, the black probe goes into the larger slot, usually to the left.
  • To see if the socket is properly grounded. Remove the black lead from the larger slot of the electrical outlet and insert it into the third one, which is usually a bit rounded in shape. Get a reading. If you see no reading, well and good. However, if you do, this indicates that the socket is not properly grounded.
  • To check if the wiring is reversed, insert the black lead into the shorter slot and red into the larger one. If the multimeter shows a reading, this means that the wiring is reversed. Although this would not affect your lamp but can be problematic when plugging in other more complex appliances like microwaves.

Possible causes for the improper functioning:


Your socket might now be working properly because:

  • The power might not be reaching it.
  • It may be improperly grounded.
  • Or the wiring may be reversed.

We have inspected the socket for each of these possible issues to arrive at a proper diagnosis.

Get your tools ready!

You grabbed a torch out of your drawer. You took out your toolbox from underneath the bed, but you’re going to need more than that. You’re going to need a multimeter. If you don’t already have one, it’s best to wait for daylight to perform this diagnosis because you can’t borrow one from your neighbors in the middle of the night. Unless they’re having a party, in which case they’re going to be up all night anyway.
Till then, you’re going to have to make your pick between too much light or no light. Till then, you can learn how to use a multimeter.
But in case you do have a multimeter, you’re in luck because we’ve taught you how to test a plug socket in just a few simple steps. Always make sure to read the safety instructions first before using a multimeter. Safety is the no.1 thing! Learn how to use a southwire multimeter.

Leave a Reply