Brake light switch pin out

[dixiepc]

I'm converting my 1992 Suburban to manual shift with a NV4500. I've got a bit of wiring to redo, but I most of it figured out. What I can't figure out is the wiring to the brake pedal switch. It has two plugs, one has four wires and I know what they are. But the other has only two wires, one black and the other gray. Does anybody know what these wires lead to.

 

[dixiepc]

Sorry, the wires are brown and gray not brown and black.