tach installation

[stoney]

i have a 1994 sws 200 series outboard and i have installed a new digital tach (original new yamaha) unfortunatly the tach just reads 00 but the trim function and oil function works properly. i would like to know how to check for the tach signal ? i know the green wire goes to the tach. can i check the green wire with engine running with a multi-meter ? and what should i look for ? i'd also like to know how to check for a signal comming from the rectifier ? any help sure would be appreciated.

thanks stoney

[boats.net]

You should get about 15 volts ac between green wires at engine and about half that between green wire and ground at tach.