02-09 Vortec 4.2L I-6 Engine and Drivetrain
2005 Trailblazer LS, 136K miles, In-line six.
Battery goes dead overnight, when cold (-0 Deg. F) two to three days (40 Deg.+ F or above)
Remove 40 amp (green) fuse #34 ("top" second from left) in under hood fuse box. With fuse removed, battery never goes dead. Have suspicion of ignition switch...