My buddy just got his after market tach for his LS1. THe LS1 is in an 89 GTA.

He has four wires off the back of it. One for 12 volts, one for ground, one for the lighting of it, and one to the ignition coil.

Oue qeustion is this, where to we tap into the coils at? We can hook them up all day on a single coil car. We just are not sure what to do about having 8 coils.

Thanks a bunch

 

You need to tap into the rpm signal wire from the computer, not any of the coil wires... The PIN # is different for different year PCM's