New to this forum on behalf of my first Chevy vehicle. Just purchased a 07 Silverado LT2 23000 mi. It intermittently had trouble starting. Finally the battery couldn't be charged so I figured a bad battery. Replaced the battery to find the old brand name battery was only one year old. Second battery in a two year old truck??? Fine for a couple of months. Then it started again. Requiring jumps sometimes, fine other times. Checked all of the fuses - fine. Don't plug anything in or leave anything on when it is stopped. I began watching the indash voltmeter. I believe I can predict the problem when the running volts are less than 14V but still >/~ 12. I will disconnect the battery when it is parked. Then no problem starting. No problems for awhile then repeat. We've been getting hammered with rain this spring but can't completely relate the problem to that. Checked wire connections on alternator - fine. I need to bring it back to the dealership but I'm sure it will fine when they try to troubleshoot. Any suggestions?

 

Have you had the alternator checked???

 

sounds like either a weak alternator, which is strange considering how new the truck is,or a dirty alternator ground perhaps, or you have a parasitic draw problem, which isn't really something you can diagnose, you'd need to take it somewhere.