The one I bought has decent size wires so easy to fit crimp connectors to. I used a piggy back spade for the brake switch connection, and then bullets for the indicators.
I was trained to fix radar and telecommunications equipment right down to electronic component level, a system would have tens of thousands of components, and yet I look at this diagram and think...not for me!
Boy have I become a luddite.
It's easy to understand your confusion. The diagram omits to show the convention of putting a dot where intersecting wires are connected. No dot where the wires just cross diagramatically.
I have put a sounder onto the indicator relay of my '74 4/4. It makes such a racket that pedestrians in the street wonder what the noise is. It's a mechanical device (think relay that cycles it's own power) and sounds aweful. I must change it for something subtler.
As a point of interest does the Audicator work with hazard flashers? Or should I say is inactive when hazards are on? Ooops just noticed Paul's post above!