The GPS might have it's own fuse. See if there is one in the plug part of it.
As far as most fuses for the interior, they are typically located either under the dash on the drivers side or with the drivers side door open, on the side of the dash. Remove the fuse panel, and turn it over. There should be a kind of map telling you which fuse is for what. There may even be a tool to remove the fuse as well as spare fuses on the underside of the panel. If you still have trouble, check the owners manual if you have it handy. Look in the back of the book in the index to easily find the chapter.