Help with Lcd marine meter

[Gramas80]

I also have green & red wire, also green & white ????
What are these for?

[boscoe99]

Try them and see what happens?

With 12 volt positive applied to the yellow wire and the black connected to the black wire, apply a ground to first the green wire with red stripe and then the green wire with the white stripe.

What lamps illuminate when the wires are grounded?

[rodbolt17]

when the green/red is grounded it should light the red lamp.
when none are grounded you should have a yellow lamp.
when the green/white is grounded you should have a green lamp.

they are from the oil visual indicates from the engine.

[Gramas80]

As a novice can somebody draw it out as its easier for me to follow.
do these wires connect to control? harness from control to tacho or is there big cable to outboard like tacho signal

[boscoe99]

As a novice can somebody draw it out as its easier for me to follow.
do these wires connect to control? harness from control to tacho or is there big cable to outboard like tacho signal

Go back and read my post numbered #8. I said that there is a separate harness that runs from the motor to the gauge for the oil status lights circuit.

The harness is much smaller than the main ten pin engine harness that runs from the motor to the control box. It is normally plug and play.

A connector at one end of the harness connects to a connector in the engine pan. A connector at the other end of the harness plugs into the connector coming from the tachometer. The engine will then ground the wires as needed to light up certain caution and warning lights that are within the tachometer.

[Gramas80]

Go back and read my post numbered #8. I said that there is a separate harness that runs from the motor to the gauge for the oil status lights circuit.

The harness is much smaller than the main ten pin engine harness that runs from the motor to the control box. It is normally plug and play.

A connector at one end of the harness connects to a connector in the engine pan. A connector at the other end of the harness plugs into the connector coming from the tachometer. The engine will then ground the wires as needed to light up certain caution and warning lights that are within the tachometer.

Forgive my dumbness, this is big learning curve for me... I have the 10 pin harness, also harness from engine to guage for trim... This I take it is another lead????

[boscoe99]

Forgive my dumbness, this is big learning curve for me... I have the 10 pin harness, also harness from engine to guage for trim... This I take it is another lead????

You are not dumb. You are just unfamiliar with Yamaha stuff. Of which there can be many, many variations.

Now think about this so more. I used the term trim/oil harness, which is what Yamaha calls it. Why, because it conveys data related to both the trim and the oil systems.

Do the green wire with a red stripe and the green wire with a white stripe not go to the same connector which has the engine trim information? If they do, wouldn't it make sense that the harness that you have for the trim gauge (the trim/oil harness) also carries the information that is needed by the tachometer to activate the caution and warning lamps?

A lot of this stuff you are going to have to figure out on your own. I don't have data available for every possible engine and instrument combination that Yamaha ever issued. Do you have the applicable service manual for your motor? You should have one.

[boscoe99]

when the green/red is grounded it should light the red lamp.
when none are grounded you should have a yellow lamp.
when the green/white is grounded you should have a green lamp.

they are from the oil visual indicates from the engine.

I was trying to get him to connect the wires so that he could see for himself exactly does what, and when. It will provide a better understanding than just reading about what the system does.

Kinda like I never really got it when my Moma said don't touch the stove top burner. It did not sink in as to what she was saying. But when I actually touched it there was an epiphany; I finally really and truly understood for myself what she was trying to convey to me.

[boscoe99]

Gramas80,

I have looked and looked for a Yamaha digital display multi-function tachometer that has but one connector on it and can find nothing.

Does it look as if maybe a connector was removed at one time?

In 1987 Yamaha showed analog tachometers for their motors. In 1988 it appears that the digital display was first used but as I said, it had two connectors on it. See illustration below.

How many connectors are on the other harness that you have which runs from the motor to the dash?

[Gramas80]

Will take more detailed pics tomorow as I've untied all tape round wires, I know guage has 2 plug connectors coming off it

[boscoe99]

Will take more detailed pics tomorow as I've untied all tape round wires, I know guage has 2 plug connectors coming off it

Are my eyes really that bad? All I see in the photo is one connector.

[Gramas80]

Are my eyes really that bad? All I see in the photo is one connector.

Defo 2 on my guage although I also used google pics to show model of guage

[Gramas80]

The photo of the tachometer wires is not as clear as it could have been. Hard to see the single green wire for the tachometer signal. Should have a bullet connector on the end. I see that one green wire appears to have been cut.

See following diagrams. 12 volt positive and ground, plus the tachometer reference signal get to the tachometer from the 703 control box via a small harness.

There should be another harness that runs from the motor directly to the tachometer connector (the round plastic one) for the oil system status lights. That harness should have round connectors at each end.

So kind of getting head round it all but just to clear one thing,
The red wire from harness that comes out controls , what is it for as above drawings show it not being connected?

[boscoe99]

The red wire is for battery power. It is there so it can be used, if needed. Lots of boaters don't use that red wire for anything.

Are you telling me that the photo shown for the gauge is not the gauge that you have? If so, I have wasted a lot of my time and boats.net's band width.