Where does this connection from my Tach go on F150?

[rodbolt17]

but
but but
in the infinite wisdom of Yamaha.

there are actually two trim/oil adapters.

one goes between the engine harness and the trim/oil harness.
the other goes between the trim/oil harness and the tach.

then there is a few tachs that will work but you have to know how to do a small bit O jury rigging.

kinda like converting 8mm lebel brass to work in a center fire converted 1878 vetteli.

but at the end of the day,if you use some kind of wire between the 4 pin engine colors I posted and the tach wire colors it works.

[NW Drifter]

Exactly what I needed! Thank you sirs.

I'll let you know how it turns out.