I am installing a Crane HI-6 ingition box, Crane distributer and Crane coil. The distributer and ignition box require 12 volts, so I'm using the original wire that went to the positive side of the coil to control a relay, that will feed 12 volts to the distributer and ignition box. Since the factory tach is part of the circuit of the original ignition wire, it won't get a signal. I would like to get my factory tach working, so I called Crane tech support. They say I need connect a half watt resistor to the tach wire from the HI-6 box, and then connect that to the tach. I would think that the tach signal from Crane's box should be the same as the what MSD or Mallory puts out, so this problem isn't unique to Crane. Has anyone else been through this? How did you resolve it? Thanks!