Good advice. Many "dead" batteries are merely a bad connection. That's one of the reasons most repair shops will add cleaning or replacing the clamps to a battery replacement.Check the battery to make sure it isn't defective. I don't reccomend Bosch batteries at all. I currrently have one on the 5.5, and I had to replace three of them in the first two days of owning them. Also make sure your posts are clean. Buy a post cleaner, and scrub the terminals to ensure that you are getting a good clean surface to mate to. If that doesn't solve the problem, then it definetly sounds like you are headed towards needing a new starter. Hopefully you don't need to do that though.