I have an 04 Expedition with 82k miles. For the past several months, the care would occasionally not start (still had original battery). I finally got around to putting in a new battery, and it started right up but when I drove it I noticed the battery light flickering, and the "Check the Charging System" on the message center. The car stalled a few miles from my house, and so I glided to the side of the road, and it started right up. This morning, it wouldn't start, so I jumped it. When I got it started, the engine ran fine but none of the gauges would work. Then when I turned the car off it wouldn't start back up. I did check the belt and it is very tight. Is this a classic example of needing to replace the alternator? or could it be something else, hopefully less costly? Thanks.