1985 90 HP tachometer

[circle hook]

the green wire is for the signal, is there any way to test this wire with a ohm meter to see if a signal is there to elimate if the tach is faulty, there are only 2 wires black witch is ground, and green should be the signal

engine model# 90ETLK
engine serial# 6H1 L 454025

Thanks Bob

[boats.net]

Check it with a AC voltmeter to see if voltage increases as rpm's increase.