How to Wire a Sunpro Tach | It Still Runs How to Wire a Sunpro Tach You should be able to do this by accessing the holes for existing wiring harnesses. Items you will need. Wire splice; References. SunPro: How to Wire a 4 Ohm Amp to a 2 Ohm How to Reconnect Car Battery Terminals. How to Wire a Pioneer DEH-1900MP. How to Wire an Autometer Tach | It Still Runs Wiring your new Autometer tachometer into your car will complete the installation. Once you have selected a mounting location, you can run the four wires that operate the tachometer. The tachometer is designed to show the engine RPMs or rotations per minute. Autometer has designed their tach to How to Install a Tachometer - OnAllCylinders Auto Meter gave us some other tach-installation tips too: Make sure your tach is set up for your engine’s cylinder count. You’ll often see an internal switch for 4-, 6-, or 8-cylinders. To avoid cutting or unsheathing the wire, use a rubber grommet when passing them through a firewall or sheetmetal. Tachometer Installation Autogage Tach Install The Autogage tachometer comes factory calibrated for 8 cylinder engines, which made it easy for me since I have the AMC 360 V8. To change the tach to operate on 4 or 6 cylinder engines, a pair of dip switches are located within the tach to make the adjustment.