Installing a tach in a Corrola

I just bout a tach for my 94 geo prism which is the same thing as a corolla... According to the booklet that came with it. I need to hook a wire up to the Negative Ignition Coil.... Can some one please help me out with this one... I cant find were to hook it up....

i have a 92 corolla and im trying to hook a tach up too. mine has electric ignition instead of an ignition coil, yours is probly the same thing. if you look at the distributer there should be 2 wiring harnesses coming out of it. there is one with only 2 wires in it, one black and one black with a brown stripe. im pretty sure the black one is negative and what you should hook it up to. i am hooking mine up in a few days so ill let you know which one it is. hope this helps