It doesn't light up or charge anymore!

It sounds like it's blown a fuse. If you look at the the end of the charger that plugs into your 12V adapter, you'll see a small blade fuse. After removing the plug from the outlet, you can just pull it out (we find it's easier if you loosen it a little with a butter knife or flat-head screwdriver first) and replace it at most any auto parts store or electronics store.