How to Hook Up a Tachometer to an MSD Ignitionby Bobby R. Goldsmith
Whether you have a factory, OEM tachometer or an aftermarket gauge, proper installation with the electric spark system is crucial to getting an accurate reading. Most tachometers are designed to plug directly into the coil or HEI port on most distributors. This OEM-centric paradigm is of little help to numerous hot rodders who have installed an aftermarket MSD ignition control system into their vehicles. Fortunately, most tachometers are capable of plugging directly into the MSD ignition control box with little trouble.
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 control box mounted on the firewall in the engine compartment.
Run enough wire to reach the MSD ignition control box mounted on the firewall in the engine compartment. Cut the wire from the spool, and strip the end of it with wire strippers.
Attach a male connector to the end of the tach trigger wire. Slide the male connector to the port on the side of the MSD ignition control box.
Attach the ground wire for the tachometer to a suitable ground plane on your vehicle. Hook the ignition/ACC wire and lighting wire to available posts on the fuse block of your vehicle.
- Be aware that some tachometers -- both factory and aftermarket -- may require the installation of a tach adapter to the MSD ignition control box to make the tachometer function properly.
Things You'll Need
- Wire strippers
- 12-gauge automotive wire
- Male and female connectors
- Volt test light
Bobby R. Goldsmith is a writer and editor with over 12 years of experience in journalism, marketing and academics. His work has been published by the Santa Fe Writers Project, "DASH Literary Journal," the "Inland Valley Daily Bulletin" and WiseGEEK.