02 Blazer LS 4WD, 4.3v6
I have kind of an unusual problem that i'm having a hard time getting to the bottom of. I've noticed that after shutting off the truck at night, that the backlight for the miles and the gear selector are still on but very faint. Also on occasions the battery will act as dead when you go to turn the truck on. It will click, and then die. all lights will go off as if the battery is dead. I can disconnect the battery, and try it again a few times and it will start, but run very sluggish until it runs for a few mins at a normal street RPM's. No extra accessories or aftermarket items are hooked up or installed at this time, because of this problem. I just replaced the battery with a 600 Cold Crank Amp battery, and had the alternator checked. Both came back good. Not sure if it's an electrical short, BCM, or something more deeper that I need to be looking for. Any help would be greatly appreciated.

 

Your symptoms could be caused by the beginning of an ignition switch failure. Check out the link in my signature below for some information into that problem.

You could also have some crossed wires under the dash. Has there been any recent work inside the dash?