Hi, snagged a 97 coupe gt grand prix for 300 bucks that needed an alternator. replaced alternator, jumped it and it ran good, stayed running and no problems at all. let it sit for a week fired right up. tried to start after a week of sitting, no cranking at all, no interior lights turned on or nothing. jumped it for a long time and it finally started so i let it run for 10 minutes. tried to start it this morning and it was completely dead. battery isnt that old. Any suggestions? Thanks