Yamaha LCD meter wiring diagram

[utfyrfytr]

I am installing an 89 70hp 2stroke on my fishing boat.I would like to use the Yamaha multifunction meter that came with the motor. I am most interested in having the tach the low oil and the overheating warning buzzer working. A couple of the wires have been cut so I am interested in tracing out the wiring diagram to see if I can get it working. I am not sure exactly what meter I have but in my research it most appears to be a 6Y5. I will include a couple of pictures for reference. Thanks for any help you may have.

 

[boscoe99]

The tachometer and its lights are unrelated to the warning horn. That is, the horn will sound and the motor will go into RPM reduction mode even if there is no tachometer installed.

What type of Yamaha control box do you have?

 

[utfyrfytr]

If you are referring to the remote it is a 703.
So are you saying that the warning horn is part of the remote and not the meter?

 

[99yam40]

If you are referring to the remote it is a 703.
So are you saying that the warning horn is part of the remote and not the meter?

that is correct
but the meter will indicate what the problem is so you don't have to guess

 

[boscoe99]

Tachometer connection for power, ground and tachometer signal will look something like this.

 

[utfyrfytr]

Ok, so if I just use the 10 pin wire harness I will have a warning horn for the low oil and over heating. I would still like to use the gauge for a tach so I know what my RPMs' are. I guess I will just hook up what is obvious and see what I have working on the gauge and go from there.

 

[boscoe99]

The black wire, the green wire and the yellow wire will give you RPM information on the tachometer.

Other wires are used to for the oil status lights. I don't think that vintage tachometer has an over temperature light.

 

[utfyrfytr]

Thank you so much for the information. That really helps.

 

[boscoe99]

If you need help making the lights work, holler.

 

[utfyrfytr]

Will do, thank you.
Another question and if you don't know I will ask the group. On this 70hp Yamaha motor, when I purchased it, I was told that the water pump was going out and needed to be replaced. We ran the motor for just a few seconds and it sounded fine and there were no signs of over heating and it had good compression. I pulled the lower leg to replace the impeller and found it completely shot, (see picture) Do you believe there may be a problem with pieces of the impeller blocking any of the water passages? Is there any way to flush the cooling system?

 

[Scott Danforth]

You need to find the missing bits of impeller

 

[utfyrfytr]

Thanks for the reply. Do you have any ideas on how? I have found quite a few pieces but I have no idea how many there are or where they may be. Is there any way to flush that motor other than with a pair of muffs?

 

[Scott Danforth]

Don't think you can flush it, you may be able to back flush parts of the system. I would plan on it being more of a borescope, and mechanical retrieval process. May need to pull the power head.

@boscoe99 will have more experience here than I would

 

[utfyrfytr]

Thanks, I just put out a new thread.

 

[99yam40]

I answered you on your other thread