Hobbies Cars & Motorcycles How to Test Your Car's Accessory Socket or Cigarette Lighter Share PINTEREST Email Print Martyn Goddard/Getty Images Cars & Motorcycles Cars How Tos Basics Reviews Classic Cars Corvettes Mustangs Tires & Wheels Motorcycles Used Cars Trucks ATVs & Off Road Public Transportation By Matthew Wright Matthew Wright Matthew Wright has been a freelance writer and editor for over 10 years and an automotive repair professional for three decades specializing in European vintage vehicles. Learn about our Editorial Process Updated on 05/24/19 Your cell phone won't charge. Your GPS won't power up. You can't light your cigarette. What's going on? Whether your car has an old-fashioned cigarette lighter or a 12V accessory socket, it's easy to troubleshoot the problem when either one goes on the fritz. Either you've blown a fuse or something is preventing the socket from making good contact with the lighter or your accessories. Check for Debris or Objects If your car has a 12V accessory socket or cigarette lighter that stops working, the first thing to do is check to make sure there isn't anything inside. Everything from dirt to lint to bits of paper and even coins can easily get stuck inside, preventing contact or shorting the fuse. Just grab a flashlight and shine the beam inside. If you see anything, be careful how you remove it. If it's dirt or small bits of paper or debris, grab some canned air and blow it out. To remove a coin, get a pair of tweezers and carefully extract it from the socket, taking care not to touch the circuit inside. Test the Power If nothing is obstructing the socket, move on to testing the power. Obviously, you can't test your 12V socket like you would your cigarette lighter socket (by actually plugging in the lighter), but it's still easy to do. All you need is a simple circuit tester to see what the story is. Place or attach the clip end of your test light to the outer frame of the socket. You can just hold it there if it won't clip on. Then take the long pointed end of the tester and stick it all the way into the socket until it touches the back. Try not to touch the sides of the socket with the probe since it will blow a fuse. If the tester lights up, you've got juice. Be sure to try it with the ignition in the "on" position, since most 12-volt accessory plugs are switched on and off with the car. If you get no light, it's probably the fuse. Otherwise, the culprit is either the socket itself or your accessory's plug or charger. If your accessories check out, then you're dealing with a short somewhere in the circuit. At this point, you can trace the wire to the socket to see if it's become disconnected or loosened. If you can't find the wire, or if it seems to be secure, then your next step is to take your car to your mechanic for further investigation. Replacing the Fuse Dead fuses aren't uncommon. They usually happen with age or by plugging in an accessory that draws too much power. Thankfully, replacing the fuse is an easy fix. Your owner's manual should tell you where the fuse panel for your car is located, which in turn will indicate where you can find the fuse for the power socket. Make sure you replace it with one that has the same amperage. If by chance the replacement fuse blows, then you're looking at the possibility of one of the two problems outlined above: Bad accessory plugs or a short somewhere in the circuit.