The stock tach wiring has a grey wire that was supposed to be for oil pressure warning light but Redline didn't put a oil pressure sensor on the engine so that doesn't need to be used. There is a white wire with orange or red stringer that is for the water temp warning light. The black wire is ground, the pink wire is ignition 12 volts, the solid white wire is the tach signal. There may also be a yellow light wire also. Some of the Autometer tachs have a 4 cylinder single pulse connection and a 4 cylinder dual pulse setting. Others just have a 4 cylinder setting. Use the single pulse setting or the 4 cylinder setting.