I just bought a blazer last week on Tuesday, prior to buying it I test drove it, at that time the battery was dead they jumped it, it ran fine. They replaced the battery prior to me buying it. I got it home and drove it Wed. it ran fine no problems. Thursday morning, no go. Friday I jumped it, had it tested it looked to be the alternator. Replaced the alternator and it ran fine both Friday and Saturday morning. Coming out of work Sat. night, it acted as though the battery was dead, turned the key twice and nothing on the third try, it turned over. Sunday morning, DEAD yet again. I did buy a new battery, it is 720 amps and the old one was 660. My question is, could it have been the amps or am I maybe looking at a new starter or something more serious? Today will be the true test to know whether or not this battery will work.