I purchased a tach supposedly from a '63 cat. I wanted to test it but the wiring is a little different than my '65. This is the tach with the cup rather than mounted in the console. It has three wires, a white (lights), a black (ground connected to the cup base) and a blue connected to an insulated terminal on the back of the tach. I was expecting to see two wires (other than the black and white). One for power and one going to the coil. Where does the blue wire go and am I missing a wire? There appears to be no other connections on the back of the tach. Thanks Rick
The blue goes to the negative side of the coil.........The white is the lamp inside as you already know.......That is how mine is wired and that is what the 65 manual says anyway.....The coil needs no external power to work,its all done off the power from the coil.......Just needs to be grounded and the blue to the negative side of the coil.
