Americanmuscle, GENERALLY, power goes to your (A) pin, top left on your pic. Ground is bottom left on your pic, I believe it's (D). And (B) is top right, part of the tranny overheat circuit. The reason I say generally is because GM had like 37 different ways they wired up the TCC. So double check.
If you want to control the TCC with a toggle switch, run power to (A) through a toggle switch, and put a jumper between the other two contacts.
The torque converter will lockup only when the tranny is in fourth AND you have the toggle flipped on.
Wire it up like this without the toggle and the converter will lock up every time it shifts to fourth gear. Hope this helps.