Set the multimeter to the correct voltage type: AC for outlets, DC for batteries and low-voltage circuits
Plug the black probe into COM
Plug the red probe into V
Turn the circuit or device on
Touch the black probe to the negative or neutral side
Touch the red probe to the positive or hot side
Read the display
Compare the reading to the expected voltage
If the reading is zero, check the meter setting, probe placement, and power source
If measuring current, move the red probe to the A or mA jack and set the meter to current mode
Break the circuit and place the meter in series
Never measure current across a live power source
Never use the resistance or continuity setting on a powered circuit
Keep fingers behind the probe guards
Use the correct range if the meter is not auto-ranging
Remove the probes after testing