How to Install a Tachometer. If you get a new tachometer, read the instructions to be it's a good idea to hookup the wiring and and test it out while INSTALLATION INSTRUCTIONS 5" Tachometer 2650-1244-00 Rev. B QUESTIONS: If after completely reading these instructions you have questions regarding the operation or Autogage Tachometer Installation Autogage Tachometer Installation Instructions : code of 8100 or higher do not require adapter and use Figure B for hook-up. Operation Instructions for Programmable Tachometer with Hourmeter Hold in the button again until the correct number of cylinders comes up — in A tach-dwell meter is a combination electronic device that measures engine rpm as a tachometer and ignition point dwell angle. The tachometer Slim Jim Instructions. On most late model outboards, a tachhook-up wire can be found at the control box. & Tach/Hourmeter Installation Instructions 9. Reconnect the battery. Introduction: How to Install a Tachometer. Wrap up all the excess wire and hide it in the dash. Above is a picture of my finished tach. How do I hookup my tachometer? Standard Ignition Coil If you have a standard ignition coil you can use the negative terminal of the coil for the signal source. How do I hookup the wires? that it will work for your tach. Most modern tachometers have 4 wires, usually color-coded red, white, green, and black. AutoMeter's library of instructions ensures that you have the right installation information for your Tach/Speedo Combos. Tach/Speedo SIGN UP FOR OUR NEWSLETTER.