Yamaha tach wiring

[typhoon]

How do I wire this one up?

Regards, Andrew

 

[haventaclue]

Green is the tach sig.,the yellow is 12v and you are missing a ground.Anywhere on the metal of the tach body.
Has this tach worked before or is this new to you? .http://www.marineengine.com/boat-forum/showthread.php?248864-70-ETLG-Tach-Problem. Here is a link to a thread in the Yamaha section