I am installing my MSD Digital Window switch today. I am suposed to hook the tach wire to one of the four wires at the coil. Which one do I hook it to? On the main coil pack hook up, there is 7 wires on the plug for the whole bank. Can I tie into one of these? Which one?

 

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Are you suppost to go to the coil input signal or to tach signal produced by the PCM?

 

my tach wire i hooked to was white & if u unbolt the plug from the pcm on the bottom they are numbered i was told pin #10. worked for me.

 

Like JRacing said... tap into it straight from the PCM, and you can then route the wire through the hole where the PCM wires go through the firewall on the passenger side.