I have a fully rebuilt 4l80e all manual from tci with a trans brake and electronic lock up, but for some reason my lock up isn't engaging or at least I thought. Whenever I switch it on in 3rd gear it doesn't do anything but now even when switch is off if i go into 4th it engages super hard and drops down a lot and the car wants to stall when coming to stop signs or what not. Also if I put it back into 3rd in low speed before it stalls it'll bang in. I ran a ground to tranny to see if that is my issue still same outcome. Car has a PI vigilante 9.5" multi disk 5k stall with lock up. Now I am thinking of one other thing that may be my issue. The tranny is in a 00 f body that was regularly a 6 speed. Where the new pigtail goes into the tranny it is pressed snug against the trans tunnel. Maybe I am getting a short from there by the t brake and reverse work great. Please any input would-be awesome. !!