Tach wires?

[TarppnChaser]

Hey guys,

Have a project boat / motor.

Have put a 2000 Yahama 150 TRP on an older ShallowSport. There was an older Yamaha carburated 115 on the boat.

Using the old controls... Iginition harness matched up. Tach does not.

From boat control.. 3 wires : 1 - Black red
1 Yellow red
1 Green

From newer motor 1 Black red
1 yellow red

Several others ... no green that I can find.

What goes to the green?

Thanks,

TC

[boats.net]

What year was the 115?
Do have Yamaha gauge or aftermarket?
If Yamaha is it a digital gauge?

[TarppnChaser]

I would guess around 1985 on the 115 yahama.

Am not near boat... no idea what brand tach.

It defininitely not digital.

Thanks,

TC

[boats.net]

If it's a non-Yamaha gauge then connect to yellow, green and black wire at ignition switch.
Yellow wire at key switch= key on power(12V)
black wire = ground
Green wire= tach signal