Vetus Tach for Yamaha Outboard
Just bought a new 25 hp hi thrust Yamaha and would like to use the
Vetus tach I have (off the "free shelf"). I understand that the Yamaha has a tach wire on the harness. The Vetus tach has an hour meter ( one good reason to use it) and the connections on the back are "+", "-", "W", and "N.C." So I believe the "W" should be connected to the tach output from the Yamaha. Correct? What would the purpse of the "NC" (normally closed) connection be? And how can I set the hour meter back to zero (reading 1775 hours now)?