Okay... see if this helps. In the bundle I am talking about, at least on my car, there are 10 wires. Violet large(about 4x larger than the other wires), violet small(the O2 sensor signal wire), pinkish/red, beige, black, black w/ white stripe, brown, blue w/ white stripe, yellow w/ black stripe, and green. This bundle is coming up from under the car running next to the passenger side header. It should have some heat wrap on it. It has the oxygen sensor wires, starter wires, and I think some of the ABS wires. The violet wire I tapped into had no stripe on it. It was a solid violet small wire. You are probably going to have to trace it, although I am willing to guess the solid violet wire on your car is probably the right one. You have to be sure you are tapping into the right one. If you hook the gauge up to a 12v source, it will toast it. The voltage of the signal wire bounces back and forth between 0 and 1volt. If you have a volt meter you can test to see which one is right, but you of course have to strip a little bit of the wire. Your best bet at this point is to trace the wire.