Project Revision

In the midst of re-wiring my build (Pro Touring 1968 Firebird, www.project-revision.com) and have a question regarding the brake switch. The motor is a supercharged LS2 with a 4l65e.....The donor harness is from a 2001 Trans Am,and I have the brake switch to match. Although I have read the post on here as to how this is done, I'm still unclear as to how to hook up the tcc side of the switch. It appears one side goes to 12v (i assume from the fuse box), while the other apparently goes to the tranny for the converter lock up......question is this......does the tcc wire have to originate from the ECM directly, or is there another location that I can perhaps tap into?!?!? The ECM is already tucked in behind the drivers side fender, making access nearly impossible without dismantling the body.....any help would be greatly appreciated!!!

Brett
www.project-revision.com