Not alot of information here, like what brand and part number tach do you have, what remote controller you have. That being said, here is a discussion similar to what you need ( I think). Specifically post #5 for the drawing. If it does not help, come back with the info I mentioned and also a picture of the back of the tach you have. http://forums.iboats.com/forum/engi...rcury-40hp-tach-install?p=6515628#post6515628
