I'm really sorry buddy but I am curious about your BCM as well. It is just that the drl lamps are controlled individually by the BCM and after it was changed you now say you have a shorted driver for the LH drl. Where did the BCM come from? Was it new, used, or 'remanned'? And just a quick FYI if it or the box it came in says 'cardone' on it then you likely got taken for whatever you spent on the junk.
This problem is hard for me to diagnose from this distance. If I were there I would scan the car with my Snap-On Verus Edge and I would talk directly with the BCM and this alone would give me so much more information that I could ever hope to get from this back and forth in a forum. Once I ran some tests and made sure the BCM was operating properly I would begin the process of tracking down your problem which might be a chaffed wire somewhere, or it might be a loose connection somewhere, or it might be a bad relay, or it might be a bad column lock motor. Either way it is absolutely impossible to backprobe from so many states away. I wish I could help you buddy. You are in a dark place ATM. You need to find a way to communicate with the BCM with a high end scantool so that you can probe the pin coming out of the BCM to energize the LH DRL and command it on and off to test that driver.