How to Build an Electrical Circuit Tester

How to Build an Electrical Circuit Tester
Written By
Stephen Benham
Stephen Benham
Published: Feb 9, 2011
Updated: Nov 20, 2021
2 minute read

The chances are you have the few items needed to build the tester in your garage.

Things You Will Need

  • AWG 16-gauge wire
  • Lightbulb
  • Lightbulb holder
  • Small knife
  • Wire strippers
  • Screwdriver
  1. Check the voltage of the electric circuit you need to test. This determines the type of lightbulb you need for building your electric circuit tester. For example, if you want to test a 12-volt circuit you need a 12-volt lightbulb, and if the circuit's 24 volts you need a 24-volt lightbulb.

  2. Cut two strips of AWG 16-gauge wire using a small knife. Cut each strip about 12 inches long.

  3. Use a small knife or strippers to remove 1/4 inch of outer plastic off one end of both strips of wire. Remove 1 inch of outer plastic from the other end of both wires. Twist the exposed metal wire so the strands stay together.

  4. Attach the two wire ends that you removed ¼ inch of plastic from to the terminals on the bulb holder. It doesn’t matter which wire attaches to which terminal. Loosen the terminal screws using a screwdriver, then insert the wires under the screws and retighten.

  5. Insert your lightbulb into the bulb holder. To test a circuit, simply attach the ends of the two wires you removed 1 inch of plastic from onto the terminals or wires you’re testing. If the lightbulb illuminates, the circuit is fine. It the lightbulb doesn’t illuminate, then there’s a problem.

The Drip Cap

  • Finding problems in electrical circuits can be a difficult and tedious task.
  • Check the voltage of the electric circuit you need to test.
  • Use a small knife or strippers to remove 1/4 inch of outer plastic off one end of both strips of wire.

Photo Credits

light bulb image by Zbigniew Nowak from Fotolia.com

light bulb image by Zbigniew Nowak from Fotolia.com

Stephen Benham

Stephen Benham has been writing since 1999. His current articles appear on various websites. Benham has worked as an insurance research writer for Axco Services, producing reports in many countries. He has been an underwriting member at…

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