How to Locate a Bad Wire Using a Multimeter

By Andrea Walk

Continuity is the ability of a wire or an electronic component to carry applied voltage or current through a circuit. Some circuits intentionally use diodes or resistors to shunt the flow of voltage or current through it. This is to prevent electrical shorts. A loose, poorly soldered or malfunctioning wire can render a circuit useless. If a bad wire is suspected for causing a malfunction in any piece of electronic equipment, the wires can be tested easily with the use of a digital multimeter. Digital multimeters are hand-held diagnostic tools that measure in several different modes including voltage, amperage, capacitance and resistance.

Things You'll Need

  • Phillips screwdriver
  • Multimeter

Step 1

Unplug the device that will be tested out from the electrical outlet or the voltage supply.

Step 2

Turn the multimeter on and set it to the "Ohms" setting. If the multimeter has a specific "Continuity" testing mode, switch it to that setting in lieu of Ohms.

Step 3

Place the negative meter lead to one end of the wire and the positive end to the other end of the wire. If the resistance reads "0" then the wire is bad.

Step 4

Test wires in this fashion until the location of the bad wire is pinpointed.