Pin out for 7 way trailor plug..

Now my brain is going nuts... the center on mine is black not yellow. Gonna have to trace my wires. But with a flat 4 the yellow is a turn signal right.

Those I posted above are not necessarily the wire colors. They are supposed to be but depends on who wired them and if they had the right color wire or not. The colors should also be written in the plastic by the screws. I believe in the four wire yellow is a turn or taillights. I cant remember now either. I know a 4 wire has gr, br, and yellow, and white for ground. i think 95 and up gm put all the wires in a loom at the back all you had to do is put the plug on. at the front the heavy gauge 12V has to be hooked to the fuse box and the blue ran through the firewall to the br controller.

ahhhh what a mess i created!!! on a more positive note...because the center of the plug is removable i think i will just back up to the trailor and play "what wire makes what turn on" and just go from there lol