98 ford taurus wont start?

I have a 98 ford taurus that ran fine until one day it wont start. You stick the key in and it chimes letting you know the keys inserted and the power will work but once you turn the key the power dies. You have to let it sit for a bit before the key will chime again. After you turn the key the horn wont work either. Had the battery checked and its fine. It doesn't try to kick over at all though.