Brake Controller Which Wire Do I Connect To The Electric Brake Controller On A 1993 Suburban?

Which wire do I connect to the electric brake controller on a 1993 Suburban? - brake controller

The schematic with the game, I can be bought much to be desired. It seems that there are 4 cables coming out of the houses in the brake pedal occurs. What is the correct connection to the electric brake controller? I had no intention to tow a trailer with electric brakes this weekend.