*** lighter not working

The lighter elements go bad a lot, you can get them at any auto store. If it's the socket (The female part), and your navigation doesn't get power from it, you can also replace it if it looks rusty or damaged. First make sure your fuse is good to it. If yes, you need to get at the socket where you will see two wires connecting to it. One is a ground, and the other is positive from your battery. If you have 12 to 14 volts between these, your socket is bad!