1999 Mazda protege, 170,000 miles. I recently got new alternator belt and power steering belt 3000 miles ago and tightened them so they would stop making a screeching noise. I was driving on the freeway for about 30 miles, and then pulled into a restaurant. When i went to start my car my a;alternator belt started screeching and snapped off. The car immediately started over heating and the battery light came on so i pulled into a mechanical shop. My friend told me it might be the pulley but i don't really know, what might be a price?