How to Use a Voltage Tester

The black and red probes of an ordinary multimeter.
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What You'll Need
Voltage tester
Plug tester
What You'll Need
Voltage tester
Plug tester

A voltage tester is a simple device that checks for electrical current passing through a circuit. It is very helpful when doing any kind of DIY electrical work, such as wiring or installing light fixtures, or troubleshooting household devices, as it can warn you about an unsafe situation by detecting if electricity is still flowing before you find out the hard way.

You can also use a voltage tester to check if a wire has sufficient voltage to power up certain electrical devices and machines. How you use this device simply depends on what you want it to read.

Step 1 - Choose Which Voltage Tester to Use

There are actually several different types of voltage testers. The simplest kind is a neon, two-wire tester that can measure from zero to 500 volts. This type is also the least expensive. The easiest to use, however, will be a digital multimeter. Once it is connected to a circuit via the red and black probes, it can provide an instantaneous reading of voltage, amperage, or resistance depending on the setting you use.

Step 2 - Make Sure it Is Reliable

sign that reads high voltage

Ensure that the device you are using is working properly before you need it for a task. Turn the tester on. On some models, a light on the housing will turn on when the probes are touched together, on other digital models the screen will turn on.

Afterward, with the meter on the proper scale, test it on a live circuit with a known voltage to check if it reads correctly.

Step 3 - Set AC or DC Voltage and Voltage Range

Set the voltage tester to AC or DC depending on the current you want to check. Electrical outlets in homes use AC, but car stereos use DC, so make sure you know which you need to use. Also, set your meter to the appropriate range. Residential outlets typically have 120 to 220 AC voltage, while appliances such as car stereos have a 12 to 14-volt DC range.

Step 4 - Check for Voltage on Electrical Outlets

To check an electrical outlet in a home or office, insert the red and black leads into each of the slots on the outlet. When the light on the voltage tester housing illuminates, it means that the outlet has voltage. If you need to know how much, you will need an analog or digital multimeter specifically.

Step 5 - Use a Plug Tester


You can also add a plug tester to your voltage meter to test receptacles. Again, when the tester lights up, the receptacle has voltage. You can also check if the receptacle is correctly wired with this tool by checking whether or not the circuits are all complete.

Step 6 - Check for Hot Wires

A simple, pen-like voltage detector can be used to probe for any hot wires in your electrical. This variety of tester isn't sophisticated, so it can only be used to check if wires have voltage up to a certain point. However, this will still be suitable for testing home wiring.

Using these basic steps, you should be able to get almost any information you need about your electrical and appliances with a voltmeter. For anything more specific, try consulting your device's instruction manual.