The Autogage tach I ordered just came in. The instructions say to hook one of the wires up to the negative on the coil. How do I do that on a stock 84 Blazer? It also says to hook a wire into the 12 volt ignition switch and another into the 12V dash lighting. How do I hook these up? Does my truck have an electronic ignition? If it does the instructions say to hook the wire to the tach terminal on the elctronic igntion. Where is that located and how do I hook up all the wires to it? You can probably tell I don't have much mecanical skills, but I gotta start somewhere.