The locks do not work.when I replaced the fuse it keeps arcing out. What would cause it?

Most likely you have a short in the harness for the locks. The most common place I find is in the drivers door harness where it keeps flexing to allow the door hinge to move. There could be other areas of issue as well but any time you have a fuse blowing immediately it is a serious problem with that system and should be checked out by a qualified person.