Step 1
Familiarize yourself with your multimeter. There are different types available, and reading the manual provided with yours aids you in using it correctly and getting accurate readings.
Step 2
Attach the red and black leads to the multimeter. Match the colors, if available, or attach the black lead to the neutral port and the red lead to the positive port.
Step 3
Unplug the washer and dryer. Not only is a power source dangerous to you, but it can also interfere with your readings, giving false readings by allowing the current to bypass the circuit you're testing.
Step 4
Access the circuits in the units. In washing machines, circuits that can be tested are the lid switch, the water level switch, the water temperature switch and the water inlet valve. Use the owner's manual for your washer to locate these components. In dryers, locate and test the terminals visible on the heating unit and thermostat.
Step 5
Choose the circuit to test, and test by placing one lead on each terminal. Terminals appear as metal prongs extending off the circuit. When testing a circuit for resistance, look for a zero reading. Resistance, or a reading higher than zero, means the circuit is open and not conducting electricity the way it is supposed to. A closed circuit, reading at zero, is working properly.