hey hey everyone!! new to boats, we have a 12.5 foot fiberglass vangaurd skibee, with a 1980 johnson 70. one of my many questions is does any one know what wire is the signal wire to the tach? i need to no what wire to tap into on the motor so that i can get the tach wokin. i know that one wire goes to the key (hot) and one for the bulb. i just dont no wich wire is the signal wire on the motor. man im such a rookie but i am very motivated!! any advice would be great!!