97 corolla Tach Wiring?

I have a 1997 corolla that I bought a tach for, and i'm wondering if anyone knows how the wiring goes to the distributor, or which wire it is. Any feedback or wiring diagrams would be appreciated!

read my post on non tach to tach install... its good

if its an aftermarket tach i beleve there are four wires
black:ground
red:acc
yellow:12v power(straight to battery)
green:negative side of ignition coil

i want to know what is considered the negative side of the ignition coil? does anyone have a detailed summary? or a picture or something? It's an aftermarket tach, that gets mounted on the dash of my car. I want to know how to hook it up to the distributor, I have the rest figured out.

you can just tap off the ignition module on the wire I posted on for my post. Its about 15-20 posts down or so "non tach to tach install."

One of the pictures I took of the ignition module and the wire to tap off of for a tach signal.

the negative side is clearly marked with a (-)