That is a fuse underneath your hood. It's usually on the driver's side in a box, which is usually a 20 amp fuse ina yellow casing.
If you've had any of these problems:
Interior dome/reading lights (the dash lights, head- and tail-lights still work)
- Power locks (both the door switches and the remote fob capability)
- Radio/CD/Cassette player (though the unit will still show trim lighting)
- The trip odometer memory (which would reset each time the car was shut down)
this may be the case.
