70ETLG tach question ( 1988 )

[dngharvey]

Yamaha tach # 6Y5-83553-00
Problem: purchased this tach with oil level lights, appears oil lights won't work due to age of motor and not all wires needed are available.
Now, just hoping the tach part can be made to work. green and black are no brainer and indicated on instructions and wiring diagram in the manual. Have been told it will need a keyed yellow wire to work, but where would it connect ?
I have the green and black, along with a red ( always hot ) and the keyed yellow coming from the side control box. Is it possible the tach hot is picked up thru lights or oil level harness ? Does not look logical, but I'm baffled, and need some input.
Going to take someone smarter than me !
This motor runs like a champ, just want to keep an eye on her ! Thanks much.

[rodbolt17]

the green,red,yellow and black leads from the control box are the tach leads.
the oil and over heat visuals are from the green sometimes green/white,oil lamp green when closed and yellow when open.
and the green/red wire controls oil lamp red when closed.
the overheat is a pink,not to be confused with the horn pink.
these go to the helm via a trim/oil warning harness.
I still dont know if your old motor needs the converter moule.
dont know if I have a rigging guide that old.
in 1988 I was working on gray boats not play boats.

[dngharvey]

Thank you for your service to our country, and thanks for your help. I downloaded a manual that includes this unit, but is not very specific.
A lot of the wires you mention are missing on this old '88. Was told by the going out of business marina that it would work, but starting to think not.
Next question, module you mention, or is there a tach that will work ? Now that the big hole is in the dash ??
Regards, Dan H

[rodbolt17]

can you post a picture of the front and rear of the tach?
even then I am not sure I can help much.

[dngharvey]

first attempt to send photos

harveys509@gmail.comEffort to send photos, thanks, Rodbolt.

[99yam40]

If you would like to bring the post back up to the top all you have to do is reply to it and just say

^^ Bump^^

[rodbolt17]

coming off the engine oil tank switch you will find a connector with a green wire and a green/red wire.
the green goes to the oil lamp green light and the green/red goes to the oil lamp red light.
yellow goes to key on 12V.

[dngharvey]

coming off the engine oil tank switch you will find a connector with a green wire and a green/red wire.
the green goes to the oil lamp green light and the green/red goes to the oil lamp red light.
yellow goes to key on 12V.

Thanks, Rodbolt....but I'm still trying to determine if the tach can be made to work. No longer care about oil lights. Don't think there are enough wires for them.
From looking at the photos, do you think tach will work ? Do I need a module ? If so, how can I find one, as I'm not even sure what one is.

[dngharvey]

^^ bump ^^

[rodbolt17]

then only thing I can say is hook the yellow to the 10 or 9 pin main,hook the green to the 10 or 9 pin main and hook the black to the 10 or 9 pin main.
they changed all that while I was still working on gray boats.
in my area all those motors have long since dissolved.

[dngharvey]

I'll give it a try and report back. Thank you.

[dngharvey]

bump......tach working !! Don't ask me how, but wiring the light with " key on yellow " did the trick. Local shop figured it out after the 6th shop manual.

[99yam40]

Does not make sense to have to hook light to key on power to make it function, but if it is working then let her ride for as long as she will function I guess

[dngharvey]

I agree it makes zero sense. Maybe backfeeds inside the control box or something, but it is working.
This 70 is on a 13' Whaler, way more than needed, but we bought it this way. It tops out right at 5500, sweet at 3000 !
Very much enjoying this blog, by the way.