My lighter went out and I don't know how to find the correct fuse to check to see if it just needs a fuse or if it is some other problem.
Lighter socket not functioning on 2005 Volvo S80
The fuse is located under your drivers' brake pedal area, you gotta remove two T25 screws and remove the plastic panel. You should see a set of fuses there, I know it's an odd place for a accessory outlet fuse, and it's a 15amp. Here is a screen shot of the wiring diagram: http://s53.photobucket.com/albums/g53/Samsonite79/?action=view¤t=Untitled.png
Get a test light, and check the fuses with the key on. If one side lights while the other does not, that could be your culprit.
If you get the owners manual it will have a diagram of which fuse box it is in and also what location in the fuse box then check if it is blown and replace as nessesary...