Using a Volt Meter to Test a 12 Volt Light

There are many times when you want to test out your volt lighting, but are unable to do so as you don’t know how. This project will teach you exactly how to use the right volt meter to test a 12 volt light. Electrical power for illumination is needed for all 12-volt lights. The brightness of the bulb will indicate the amount of voltage reaching the terminals on the rear of the 12-volt light. Most of the electrical power is supplied through a 12-volt battery. To check whether the 12-volt light is in bad or good performance, check the amount of the voltage from the power source along with the voltage delivered to the light bulb terminals will do the work. Here are the steps on how to use a volt meter for testing.

You will need:

  1. Voltmeter test leads
  2. Voltmeter

Volt Meter


  1. First, place the red test lead into the voltmeter connector known as “volt”. Secure the black test lead into the voltmeter connector marked as “com” before turning the main switch of the face of the voltmeter to “DC volt”. Make sure that you turn it right before committing any mistake.
  2. Then, you should press the red lead of the voltmeter to the positive (+) terminal on the 12-volt battery while the black lead of the voltmeter is pressed on the negative (-) terminal on the battery. It should be pressed correctly or the device will not function properly.
  3. The display of the voltmeter should show greater than 12.0 volts. You will need to change the battery if the voltage shown is less than 12.0 volts. If ever you need to change the battery, you should make sure that everything is removed properly and well so as not to put you in any type of danger.
  4. For the next step, take off the leads from the battery slowly. Try to make an access to the rear terminals on the 12-volt light you are testing. Proceed to check the manufacturer’s instructions on how to access the terminals on the 12-volt light as the lights are utilized for many applications.
  5. There are some manufacturers who will include a special wiring schematic that will allow you to check the circuit for problems in the wiring and switching circuit.
  6. Follow this step by turning the 12-volt light’s switch on and then touch one of the voltmeter leads to one of the light connector terminals. Perform the same steps to the other lead and light connector terminal.
  7. Next, read the display on the voltmeter. The display should show the same greater than 12.0 volts.
  8. The light will be indicated as bad if the voltmeter display shows less than 12.0 volts and the light does not illuminate.
  9. The switch or the wires leading to the light bulb is in problem if the voltmeter display shows 0.0 volts.
  10. That’s how you can properly use a volt meter to test out a 12 volt light.

Image Credit:

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Additional Reading:

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How to Test Almost Everything Electronic