ISSPRO Tach

[84FordSmoker]

I just bought a 1984 F-250 6.9L a month ago. At one time it had an Isspro tach installed with hte magneto pickup on the crank., and throuhgt the years it became disconnected. I was wondering how to hook it back up it has two wires coming from the pick up and three frome the guage: white , red, and black. One of these is for the light in the head. where do these wires go?

 

[FordGuy100]

I have this same tach on my a-pillar. I will have to go look tommorow. One of them is a power, I know that. I will look tommorow I forget