For all of you who have a multimeter thrown in a drawer or toolbox but don’t know how to use it, these instructions will help in your search for missing voltage.

If your power supply has an on/off switch, turn the power supply on. Switch your multimeter to the range that is appropriate for reading the voltage from your power supply.

An essential tool for testing light switches is a continuity tester. You also can use a multimeter by turning the dial to read “continuity.” ...

Multimeter Cost Multimeters are versatile mechanisms that can be leveraged beyond automotive applications. Even basic multimeters can measure voltage and current in household items such as switches, ...

You can then use the multimeter’s continuity tester along with a scrap piece of wire that stretches between the two switch boxes to determine the two traveler wires.