How to Test a Cigarette Lighter with a Multimeter

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A malfunctioning cigarette lighter is not an uncommon occurrence. The component comprises electrical parts that can wear out or get damaged when subjected to normal and regular use. The lighter’s fuse can blow, socket can get short-circuited, wires can become loose, and the electrical components might start passing little or no voltage.

Regardless of the cause, you can troubleshoot, repair, or replace the faulty cigarette lighter in just a few minutes. All you need is to understand the electrical parts that make up the lighter, and polish your knowledge of how to use a multimeter to troubleshoot electrical components.

If you are a first timer in troubleshooting a malfunctioning cigarette lighter, here are the bits of information you need to identify and perhaps fix the faulty parts.

Troubleshooting a Cigarette Lighter Using a Multimeter

1. Understand the essential electrical components on a cigarette lighter

Let us face it. You cannot troubleshoot a car cigarette lighter without knowing the electrical components that make up this system.

Therefore, if this is your first time troubleshooting this part, get the lighter’s manual, and check out the location of each electrical component on the vehicle system..
Identify the location of the fuse that protects against power surges, a thin coil made from nichrome, and the 12V socket that powers the cigarette lighter. A cigarette lighter cannot work when any of the mentioned electrical components are faulty, the reason why you should focus on identifying the location of each.

Basically, these are the most significant parts that you will have to test with your multimeter when looking to identify why the lighter is not working efficiently.

2. Test the Cigarette Lighter’s Fuse for Continuity

The fuse is the first part that can make a cigarette lighter malfunction. Every car cigarette lighter has a cylindrical or blade fuse against power surges. It blows up to protect the lighter’s electrical components whenever the lighter receives high voltage power from the socket.

For this reason, if your cigarette lighter has just stopped working, it would make sense to start the troubleshooting process from the fuse. Refer to your cigarette lighter’s manual to locate the fuse and detach it from the lighter.

Power on your multimeter, and plug its testing probes into the correct ports. Turn the multimeter’s selection knob to continuity test mode. Place the test leads together and ensure your multimeter beeps.

The beep sound from your multimeter confirms that the multimeter is set correctly to test continuity. Place the red test lead on one end of the fuse and the black test lead on the other end.

Your multimeter will beep if the fuse is working efficiently. On the other hand, the multimeter will not beep if the fuse is blown up, signifying that you need to replace the old fuse with a new one. The beep sound means that there is uninterrupted flow of electricity between the points being tested.

3. Test The Cigarette Lighter’s 12V Socket for Voltage

If the fuse is not dead, proceed to test the cigarette lighter’s 12V socket, another part that is highly prone to malfunctioning. As its name suggests, the socket supplies the lighter with the power needed to light up the cigarette lighter’s coil.

To test the socket’s voltage, unfasten the entire part from your car’s dashboard. In case you are a first-timer in this task, refer to your car’s user manual as a guide to help you dismantle the 12V socket from the dashboard.

Plug the test leads into the correct ports. Turn the selection dial to voltage setting, often symbolized by V with a wavy line. Set the corresponding range to around or above 12 volts, the expected working range for an available 12V socket.

With the multimeter’s black testing probe, touch the socket’s negative pole, the metallic parts inside the socket. In addition, touch the socket’s positive pole with your multimeter’s red testing probe. For most sockets, the positive pole is at the back of the socket.

Take the reading recorded on the multimeter’s screen and compare it with the ideal voltage of 12 volts. The voltage of a working cigarette lighter socket should range from -10% to +5 % of 12 volts. Anything outside the estimates suggests that the socket is faulty.

4. Check the Lighter’s Coiled Strip for Continuity

Suppose the socket and fuse work efficiently and diagnose the lighter’s coiled strip. This part completes the electrical circuit when you plug the cigarette lighter into the socket. The coil glows orange hot upon completing the circuit to provide the heat needed to light a cigar or cigarette.

When broken, your cigarette lighter will not produce that superhot glow needed to light up a cigar. For this reason, during your diagnosis, it would matter to check the coil for continuity; a test is done to identify if a part has a complete path for an electrical flow.

To test the coil for continuity, plug your multimeter’s probes into the correct ports, and turn the selection dial to the continuity mode. Place the test leads across the coiled strip. The red testing leads on the coils on one end and the black probe on the other.

Your digital multimeter will beep if the coil has complete continuity, a sign that it is in working order. On the contrary, if the multimeter does not beep, it is a sign that the coil is faulty.

5. Test the New Cigarette Lighter and Replacement Parts

After testing, you will have two options. You might have to replace some parts like the fuse and loose wires with newer components. Two, you might have to replace the entire cigarette lighter with a new manufacturer-recommended part.

Whichever the outcome, test each new part before installation. Test the fuse and coil strip for continuity and the 12V socket for voltage. Proceed to install the new parts after ascertaining that they operate effectively.

The Bottom Line

Unlike other car parts, troubleshooting a faulty cigarette lighter is not a preserve for mechanics. Anyone with solid knowledge of using multimeters to troubleshoot electrical components and understanding the parts that make up a cigarette lighter can execute the project. 

If you are looking for a procedure to troubleshoot your faulty cigarette lighter, check if the socket is working by testing for voltage and troubleshooting the fuse and coil for continuity. After spotting the faulty part, test, replace replaceable parts like the fuse, repair broken parts in the socket, or get a manufacturer-recommended lighter to replace the old cigarette lighter. It is our hope this guide provided the information you needed.

Frequently Asked Questions

How does a car cigarette lighter work?

When you plug a cigarette lighter into a 12V socket, a high electrical current runs through the lighter’s coil to create a hot glow. It is the glowing coil that provides the heat needed to light cigarettes. A cig lighter’s coil takes around 10 seconds to heat up.

Unlike ordinary, portable cigarette lighters, a car lighter does not produce a flame. This is why it is great for lighting cigars or cigarettes without posing a fire danger to your car. However, you cannot use it to light other things like candles and campfires that need an open flame.

Where can I find a 12V socket’s positive and negative terminals?

For most cig lighters, the positive terminal is found behind or at the bottom of the socket. The negative terminal is on the metal clips inside the socket. However, since the location of the terminals of a 12V socket can vary from one unit to another, it would be prudent to refer to your user manual for precise identification. That way, you will not indulge in guesswork when troubleshooting this critical vehicle component. 

Can I repair a faulty car cigarette lighter?

Issues like a blown fuse, loose wire, and wonky wiring can be fixed by replacing old parts with newer ones. You can get a technician to fix the wiring or do it yourself if you know electronics.

Other issues like a faulty coil or an excessively worn-out lighter might be impossible to replace. In such a case, you will have to replace the entire system with a manufacturer-recommended aftermarket part.

Reputable automotive stores have multiple replacement cig lighters for different car models.

Why is my cigarette lighter not working?

A couple of things can make a car cigarette lighter stop working. The common issues include a blown-up fuse, debris stuck in the lighter’s socket, and limited electrical power passing from the socket to the lighter.

Additionally, your car’s cigarette lighter can stop working due to short-circuiting, normal wear and tear, or a malfunctioning button. Troubleshooting your faulty cigarette lighter with a multimeter is the only sure way to figure out the exact reason why your cig lighter is not working.

Which fuse should I use as a replacement for a worn-out cigarette lighter fuse?

Many cigarette lighters come fitted with a 10-20 amp fuse. So, you can replace a worn-out fuse with any fuse with similar amperes to the worn-out unit. You can get your preferred fuse from an electrical or hardware shop near you or purchase from reputable online stores like Amazon.

Toby Ashby

I am an automotive specialist with over 20 years of experience in and around electronics