I have a sunpro tach, I dont know which wire to splice into, for the tach, i know what to do with the two positives and the ground, but I have no idea which wire on the coilpack that i need to run the wire from the tach that reads the rpm's, help??
had the same question a couple of days ago. Summit racing sells an adapter for vehicles that have coil packs. The adapter should fix any issues you might have during the installation. The problem: it costs $80.00
I changed my mind about installing a tac, plus the adapter all together.
Somebody in this board convinced me of buying this:
On the 3.4 you hook it to the igniter but I think with the later 4 poppers that are without a distributor there is a pin on the ECU. The ECU fires the coil pack/ignitor packs directly without a seperate ignitor. Look on the ECU diagram and you'll find it right next to the coil pack leads.
Check the online FSM for the pin number and wire color.
You should also have an instrument light lead on the tach.