Multimeters have an option to measure resistance indicated on their front panels. By switching the dial to the ohms setting and turning the power off to the appliances being measured, the status of a circuit can be determined.
- Turn off power
A multimeter tests resistance by sending a small electrical charge through the device and recording the current. If the power is on, it will disrupt the device and blow the fuse of the multimeter. Therefore, remove the battery or unplug the appliance from the wall.
- Connect the multimeter's leads and set it to the resistance reading
The red lead goes to the port marked "VA" or something similar. The black lead goes to the port labeled "COM". Turn the measurement setting of the multimeter to resistance, which is indicated by the ohms symbol. Many digital multimeters will adjust range, but analog multimeters may have ohm, kiloohm, or even megaohm ranges.
- Touch the leads to the terminals
Touch the red lead to the positive terminal, marked with a plus sign or the shorter outlet plug, and touch the black lead to the negative terminal or larger outlet plug. Although current can travel either way, it's best to get into the habit of learning which leads are which. Also, always grip the leads by the plastic or rubber housing, never by the metal tip.