The fuse for the S13's cig lighter is the fourth fuse down on the left column of fuses. (In the box to the left of the pedals.) It should be a blue 15 fuse. Anyway, just while we're on the topic, here's something you SHOULDN'T do, at least on 240sx's.
I had the same problem: cig lighter not working. So I popped the console and had a look around. I noticed that the guy who had the car before me had ghetto wired the cig to a mystery component. I say "mystery" because it was removed before I bought the car.
Anyway, to make a long story short, I ended up with an arc and subsequentially lost my tail lights, side markers, and dash. Curiously, my dome light, stereo and clock still functioned fine. It cost me a lot more than it was worth to have a shop rip the car up and find that my dimmer was blown and that the light selector (on the turn signal switch) needed to be replaced.
Yeah, not one of my proudest moments.
Moral of the story: CHECK THE FUSE BEFORE ANYTHING ELSE! LOL... if I had done that, I could've saved a bundle of money.