Analog Tach wiring for F 9.9

[horsetrader]

I have an analog Tach that I would like to use for the F 9.9. I set the tach to the 6 pole position and I ran a wire from the lighting coil (green wire) to the green wire on the tach. This particular tach has a green wire paired with a black wire and a blue wire paired with a black wire exiting the rear of the tach but there is no yellow wire. I'm guessing that one of the black wires is for power but which one? Any help would be appreciated. Thanks very much.

[boats.net]

Probably not the black wire, what kind of tach is this?

[horsetrader]

This is a Yamaha Tach. I'm not sure of the model/ part number but it looks just like the photo of the part number below. It is not new but not ancient either. On the back, it has the selector for different pole positions and the previously mentioned four wires (green, black, blue, black). Thanks again.

6Y5-83540-14-00
PRO SERIES TACHOMETER without oil indicator

[boats.net]

It should have a yellow wire, is it possible broken off?

[horsetrader]

The back of the tach is intact and nothing has broken off. However, when looking at the back of the tach, the lower portion has three circular grooves that look like holes for connections should be there. From left to right there are the letters G, Y, R under each respective circular groove. Maybe there are connectors under the plastic. Should I take the back off to inspect for connectors underneath? Could this tach have left the factory somehow uncompleted? I'm just thinking out loud. Thanks very much.

[boats.net]

The grooves at bottom are for the oil level lights on a 2 stroke engine. You can try use the blue wire for key on power and the blacks to ground to see if will work.

[horsetrader]

Well, I guess this tach is not meant to be for me and th F9.9. I rewired the blue wire to power, both blacks to ground and green to engine lighting coil and nothing. I may have to try a new tach. Suggestions for new tach part number or other suggestions would be appreciated. The engine is 2005 F 9.9 MLHD with conversion kit so I can operate throttle and shift from the helm. Thanks very much.

[boats.net]

That is the right part number (6Y5-83540-14-00) for the tach.

[horsetrader]

Thanks guys, I'll keep my eye out for one because the one I have will not work for my application.