[HUMTECH]

The ignition switch can be adjusted, if they are not installed accuratly they will leave accessory power on. Easy way to check install key halfway and turn lock cylinder forward firmly and see if truck power up. If so ign switch needs to be removed and adjusted until this does not occur, seen it and repaired it many times. As for battery draws elsewhere have seen many air suspension relays fail and cause A draw, as well as onstar, sometimes if your not A subscibed customer the gps will intermittantly look for A signal waking up the module, pull the info fuse if you dont have A subscription. Also hvac control heads and stereo amps have been know to cause A draw.