How to test the wiring in a house

Updated February 21, 2017

When electrical circuits do not work in the home it may be necessary to test the wiring to determine where the problem is occurring. Issues with an electrical system can be caused by single wires or by a short in a large part of the system. It is important to test wiring by adhering to certain safety considerations. Even if a wire seems to be dead, make sure to turn off the electricity to avoid shock.

Turn off power to the house or the room where the circuit you wish to work on is located by flipping the switch or switches in the breaker box.

Test the electrical circuit you wish to work on before touching it by touching a voltmeter to the wire. Hold the voltmeter by the insulated grip and touch the bare end of the probe to the hot wire in the circuit, which is usually black or white and located near the end of the box. Ground the other probe by touching it to metal. If you get a reading, the circuit is still live and shouldn't be worked on until it has no power going to it.

Test a wall socket by sticking a probe into both the left and the right side of the socket. The voltmeter will indicate that there is voltage coming from the socket if it is working.

Flip all breaker switches off then on again to make sure they are working. For houses with fuses instead, test wiring throughout the house for shorts by turning off all the fuses at the fuse box. Slowly turn them on, one at a time. If one fuse causes the rest of the fuses to turn off or the electricity to turn off, a circuit connected to that fuse is faulty.

Inspect all the wiring around the home for breaks. Replace them if necessary.

Things You'll Need

  • Voltmeter
  • Screwdriver
  • Fuse
  • Needle-nose pliers
Cite this Article A tool to create a citation to reference this article Cite this Article

About the Author