2001 S10 Blazer 2WD, 4DR
I have a serious short circuit that starts draining the battery VERY quickly until I pull the INT BATT fuse under the hood.

I have pulled the following fuses from the inside fuse panel:

HDLP SW, AUX PWR, RDO BATT, CIGAR LTR, CTSY LP, and PWR LKS (not equipped with Premium audio)

It seems that something with the CTSY LP circuit is causing the draw. When I replace that fuse, with all doors and rear hatch closed, the inside dome light still remains on and the battery begins to drain quickly, but I believe there is a "timeout" period for the dome light after the doors are closed.

Is it possible that the short could be elsewhere, i.e., under the hood such as the battery cables,etc. and that it is just "showing up" with the CTSY LP circuit?

Any help/suggestions will be greatly appreciated.

Update: If all doors are closed when I connect the battery, the short/drain does not appear to be happening. When I open the driver's door, the drain begins, and continues even when I keep the door jamb switch pressed in. I can hear what I believe to be the inadvertent power lamp relay and courtesy lamp relay in the body relay block "buzzing" and clicking intermittently. I believe the connections for the door jamb switches, etc. go into the BCM, but I am not sure where to begin troubleshooting from here. Again, any help will be greatly appreciated.