This is the one.. Looking at the wiring I need three wires but the one I have has only 2 wires. It is under the dash to my left. I bought an expensive steering wheel, and a while after I had it, it would blow the horn when I turned left, which was annoying, especially if someone was crossing the street in front of me. So a momentary switch was installed. Now I would like to install one that looks like a necker nob on the steering wheel. In the picture at the bottom left, there is a diagram of the wiring board.