Tachometer not working

[micky692002]

My tach. is 1 year old and the wiring to the sender on the flywheel is 1 year old too. I hooked up my old tach to see if the problem was the tach. It didn't worked. I cleand the terminals on the sender too and nothing. What do you guys think? The sender is bad? Its a Yanmar engine.

[LunaSea]

I have experienced this problem a couple times, on different boats w/ Yanmar 315s... Every time the problem was a weak connection in the main wiring harness plug....