tach is not working g - communityrude The generated tachometer signal is the gray wire that comes out of the EMM and goes to the 8-pin connector at the tach. Your tech can check the continuity of the wire and if there is the proper frequency signal coming from the EMM using the Evinrude diagnsotic software. evinrude tach | eBay Find great deals on eBay for evinrude tach. Shop with confidence. Skip to main content. eBay Logo: Evinrude Etec New Icon Tach Pro Tachometer Kit 4" Black 7000 RPM 0768007; 768007. Brand New. $369. Omc Tachometer Plug Boat Wiring Harness 10 Ft See more like this.