I believe turbomonte is right...
If it's the LED knock gauge, when I installed it, here's how I remember it. There are 3 wires to connect, positive (power), ground, and signal. Signal goes to the pink/black striped wire, I think it was all the way across to car by the ECM somewhere where I found it. You've got to splice into it. The positive wire should be routed to a accessory terminal on the fuse box, I usually plug into a free "ING" slot, I think they shut off during startup... but I'd check to be sure. Black ground I just attach to the ground screw just above the break release handle. I had to use my own electrical connectors and wire and such, but this turned out great because you can do whatever you want with routing. Some of us are anal about making it look neat!
Otherwise, by re-reading your original post, it looks like your reading the instructions wrong, the pink/black wire is the signal wire. Not the positive feed... Those are two separate wires. Hope that helps clear it up.