So I'm revisiting this years later (I'm StevenTruck). I recently got a GMC Sonoma Highrider and I'd love to install this option. For a switch, I just used the column shift lever from a 02 full size truck (plug-n-play). I tried one from a AstroVan and that one actually matches better, but you will have to grind the flat key-way to get it to fit. Conveniently, this is also a good way/time to replace that torn rubber boot that most of us have.
Anyways, My truck doesn't have that nice 7-way plug at the front of the floor console. I am willing to plug my wire into the BCM, but I can't find anything about where it plugs in (I know where the BCM is, I just don't know which connector/pin), and that wasn't in the writeup that was done. Could one of you trace back your light blue wire and tell me where it goes into the BCM? Thanks.