It's easy to test the lighter or accessory socket in your car or truck. 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. Replace the fuse and you're good to go.