How to test a light switch with a voltmeter

Very easy way to test light switch with multimeter. Make your to turn the power off at your breaker. Keep the circuit common light switch has two terminals. Multimeter measuring ohms, volts and amps.

A multimeter is used to test this switch.

If the switch is flippe the light on the tester will light , beep or the ohm value will change from .

Now that you know it works, turn your switch on, use the probe to check for power at it, then go .

Flip off the circuit breaker controlling the wall switch you plan to test. Ideally, your circuit breakers, found in the electrical panel, are labeled by room. I use the continuity setting to establish that the contacts of the switch will cl. If you have not power to the light switch , you want to make sure the power is on and coming to the box.

There are other things you want to check before you decide the switch is bad. If the breaker is okay, then the light switch is the next likely suspect. Most switches stay in service for several years but may need . I ´ve been trying to find the cause for the abs warning light being permanently lit, and this vid gave me the push in the right direction!

The common light switch has two terminals. I am presuming for this that the light switch is removed from the circuit. There are several types of light switch but the most common is the single pole single throw. It has two wires attached to it.

First, make sure the power is turned off. Using the Ohm function of the multimeter , touch one lead to each of the two screws. Brake light switches are simple (NO) normally open switches.

In time these contacts wear resulting in no signal. This can affect the brake lights , the cruise control . Testing switches or relays is another common use of the resistance- testing feature of your multimeter.