where does the tach signal come from??

[mike78]

The title says it all -- I put in a procomp ignition and the car runs great, however the tach is crazy. The duraspark is out, and the plugs are still there, and the procomp tech guy says all I need to do is hook up my box to where the signal comes from, does any one have a print they could post? Please help if you can, mike

 

[G.A. Heath]

The tach signal comes from the ground side of the coil. Your ignition module should have a tach port you can run the tach to. you may require an MSD, or similar, tach adapter in order to make the tach work properly.