We all know that when we do the swap, our factory wagons use a distributor, thus the tach doesn't work once we do a swap. (only exception is maybe with a 90 harness)
After trying to hunt different junkyards to look for a 1990 Talon "tacho Interface J602" I gave up and decided to build my own.
You will need following:
2x 1N4004 diode
1x 1N4744A Zener diode
Follow the crappy hand drawn circuit diagram below.
Follow following link to where to hook onto your coil.
Connect directly the "tach" on that circuit to your tach (white wire on C67 plug on the passenger footwell, or directly behind the tach (sorry don't have the pin right now)
This is all I needed to make my tach work, and is exact replica of the factory Tach interface. I didn't need any filters to make it work.
More pics here.
http://photoshare.shaw.ca/view/33609495 ... 716-86880/