non power brake wire

I need help finding out what wire is the non powered brake wire. I am installing a brake controller and have had a hell of a time getting to that brake switch. I'm thinking the thing would have 2 wires but it has a harness and I'm not sure at how to get to this thing. I'm back under the dash near that lovely ignition swithch harness and can't figure out how to get to that brake swich and start probing wires for the hot one when the brake is applied. Has anyone dealt with this headache yet. the lower intake went smoother than this.

thanks
Jkdon

Try looking under the dash, at least all my brake wires go to a switch under there. If you've got cruise you might have 2 switches, and you'll probably want the 1 that doesn't have a vaccum hose going to it.