Plug the black or negative test lead wire into the port on the front of the electrical meter labeled "COM." Connect the red or positive test lead wire into the port labeled "VBAT" in the same fashion. It is important that these leads are connected to the proper inputs or you may get an inaccurate reading or damage the circuit or the reader.
Turn the "Range Selector" dial to the "Batt Test" position before using the meter. If you do not see the "Test" light turn on, you will need to replace the battery. Slide the battery cover off of the back of the unit and remove the battery inside. Reconnect a fresh 9-volt battery to the receptor and close the cover.
Turn the "Range Selector" to the proper current type and range for the circuit you are testing. The "AC" side is for currents used in the United States and items made there. The "DC" side is for direct current circuits that are used throughout the world. Start at the highest voltage for the current you are using.
Place the black test lead onto the negative wire that is part of the circuit you are testing. Place the red test lead onto the positive wire of the same circuit. Hold these leads steady until you see a voltage appear on the screen. If the voltage is zero, remove the leads, turn the "Range Selector" down to the next lowest level and try again until you get a reading.