[PDF] MSD Tach Adapter PN 8920 - MPS Racing MSD Tach Adapter PN 8920 If your tachometer doesn’t work correctly after installing an MSD Ignition Control, always try to connect the tach’s trigger wire directly to the tach output of the Ignition. If the tach still registers incorrectly, install this Tach Adapter. How to Hook Up a Tachometer to an MSD Ignition | It Still Runs Strip the end of the trigger wire for the tachometer, and place a female-to-female connector to it. Fit new wire from the female/female connector, and run the wire directly from the spool through an open point on the firewall. Run enough wire to reach the MSD ignition MSD Performance Products - Official Site The team at MSD is no different as we strive to deliver the products you need to meet your performance goals. We continue to innovate and invent components and technology that deliver performance and reliability with products that are easy to use and install.