I have a 2008 GMC Sierra 1500 with the V-6 with only 53,000 miles on the clock. About once every 4 to 6 weeks I'll get in the truck and it is completely dead, as if someone swiped the battery. This has happened whether the engine is hot or cold and it will finally start after trying for an hour or two and then it runs perfectly for the next few weeks. I replaced the mega fuse on the firewall but that didn't solve it. Anyone have a possible idea? I know, intermittent problems are the worst.