probaly the alternator. i had a 1999 cougar for 5 years. the alternator wears out every 25k. i had 3 put in my car since i owned it.2 overcharged the battery and one the bearings wore out. its a bad design. its way down low on the car and gets hit by all the road debri and snaow and salt. there was also a recall on the routing of the aternator cable.