2018 Yamaha F115B (6EK) trim harness to MF tachometer 6Y5-8350T-D0-00

[Bateau_CX19]

I am trying to confirm which trim/oil harness is applicable to a 2018 Yamaha 4 stroke F115B.

Is it the single 4 pin connector harness 6Y5-83653-XX-00 or is it the dual 4 pin connector harness 68F-82553-XX-00. Or, a third option, is it neither of these two?

If it is the single 4 pin connector, and I have a Yamaha multi-function tach ( 6Y5-8350T-D0-00) with two 4 pin connectors (one male, one female), what is the adapter cable part number? Better yet, what is the wiring pinout for the connectors? I think I know some of the wire functions, but not all...

Tach 6Y5-8350T-D0-00 <----> Trim/oil cable(s) needed <-----> F150B (6EK)

I could wait until I have the engine in my possession and likely figure it out then but i am guessing someone here already knows the answer allowing me to source the correct parts now.

Thanks for any help. I can't help myself, the weather is not conducive to boat building, but I want to be ready come spring.

[boscoe99]

If the tachometer is indeed the type with two four pin connectors at each end then it will be connected to your motor via a single four pin trim/oil harness and an adapter cables.

[Bateau_CX19]

Awesome, thanks Boscoe99

[Bateau_CX19]

So, I'm back....

I found the following information (table) from Yamaha and I have received my tachometer (6Y5-8350T-D0-00). The tachometer does indeed have two 4 pin connectors, one male and one female.
Tachcapture.PNG
Then I read "'this tachometer 6Y5-8350T-D0-00' Was designed for 2004 and older Yamaha model engines but does function with newer 2005 to current model years " from the Yamaha information. That leads me to believe that this tachometer is a 2004 or later tachometer and should be OK with 2004 and later engines WITHOUT the extra harness 6Y5-85335-00.

TL;DR - I think the 2x4pin connector Tach does not need the adapter harness for a 2004 & later model engine. Yes or No?

To double check this, I looked at the wiring on the tach and concluded the following:
tachharnesssnip.png

The engine only has 4 wires from the 6Y5-83653-10-00 main trim/tach harness heading to the tach so therefore the tach should only be expecting 4 signals on this harness. Furthermore, in the tach harness, I have verified that the Gray and Pink wires are common amongst the two connectors. I further confirmed that Black/white in the female 4 pin harness of the tach is common with the Black bullet connector which is obviously ground. It appears that only Pink (trim), Gray (warning?), Green/white (temperature) and Green/red (oil pressure) are supplied on the main harness. That leaves only the Orange wire unaccounted for. I believe Orange is +5v for the old three wire trim (Black/white is ground). Furthermore, looking at the wiring on the main trim harness (6Y5-83653-10-00) these 4 wires line up as expected on the male connector of the tach.

Therefore, my conclusion and what I am looking for verification of is that for my 2018 F115XB engine to connect to my 6Y5-8350T-D0-00 tachometer, I actually DO NOT need the extension harness 6Y5-85335-00?

Good conclusion, or Bad? Should I place the order for the harness or can I save $100? Either way I will probably wait to see what if any signals are missing after installation as I have compatible male and female ends and pins so I could make my own harness (I know I'm being a cheapskate, but if I don't need the harness, I would rather not purchase it.)

Boscoe99, I am certainly NOT trying to contradict your information above and I believe adding the adapter wouldn't hurt anything, but I am starting to think it is not required either. If I have overlooked something obvious please let me know. Please don't hesitate to say 'Nope, you're wrong!' ;-)

more info:
1. Pink is breakable both at the tach and on the 6Y5-85335-00 adapter harness. With the tach is a note saying that pink must be broken for 2003 and earlier F30, F40, F50 and F60 or trim will malfunction.
2. I am not 100% clear what signal is carried on the Gray wire in this harness? Does anyone know for sure?
3. Neither the brand new tach nor speedo came with any kind of instruction sheets. Is this normal?

Thanks again for any help and if nothing else, maybe this helps someone else down the road.

[boscoe99]

Three outputs are provided by the one engine connector. Trim, low oil pressure and high engine temperature.

Those three outputs go into the tachometer via two connectors. Two inputs to one of the two connectors and one input via the other of the two connectors.

Without the adapter harness how do you propose to do that? You are free to cut and splice but that is not the Yamaha way.

[boscoe99]

No instructions being provided is normal. Instructions are not normally needed.

[Bateau_CX19]

Three outputs are provided by the one engine connector. Trim, low oil pressure and high engine temperature.

Those three outputs go into the tachometer via two connectors. Two inputs to one of the two connectors and one input via the other of the two connectors.

Without the adapter harness how do you propose to do that? You are free to cut and splice but that is not the Yamaha way.

BTW, I'm not suggesting splicing harnesses at all.

My point, and then I won't belabour it further, is that the tach I received already has pink (trim) and Gray (??) interconnected between the two 4-pin connectors (M & F).

The other two connections on the tach male are Green/red (oil pressure) and Green/white (temperature).

Therefore, the tach male now has Pink Trim, Gray ??, Grn/Red Oil and Green/Wht Temperature which I believe covers all of the inputs

The tach female has duplicated, but electrically common, copies of Pink Trim, Gray ?? so that is no longer an issue. It also contains Orange and Black/white which I dont think are being used and certainly arent being supplied by the main engine harness. Might also explain why in the adapter harness, on the engine end, these same two connections (Org and Black) are simply capped off. In any case, Black/white is also common with the Black Ground bullet connector so if a ground is expected inside the tach it will already see it. This leaves ONLY orange unaccounted for and it doesnt appear that the adapter harness addresses Orange either.

Tach wire.png

As long as Orange isn't required, and I dont think it is, what am I missing>

Im first to admit I'm on a (steep) learning curve here but I'm also pretty practical person.

[99yam40]

Three outputs are provided by the one engine connector. Trim, low oil pressure and high engine temperature.

Those three outputs go into the tachometer via two connectors. Two inputs to one of the two connectors and one input via the other of the two connectors.

Without the adapter harness how do you propose to do that? You are free to cut and splice but that is not the Yamaha way.

Did you read this again

you can try it like you want to, and if it does not work try the adapter

[Bateau_CX19]

LOL, Yes I read that, and I think I addressed all three inputs and explained my logic for each. I still think my logic holds, the adapter may not be required. The key is that fact that the tach already electrically croses two wires between the two connectors When I get the engine hooked up I will let you all know. If I am wrong, I will step up and admit it. Might even offer an apology! ;-)

THanks again for all of the valuable insight you guys offer. It is appreciated and is listened to even if I might seem to be disregarding the advice, truely I'm not. However, I do think it is healthy to question things, even if I'm wrong. That's how one gains experience.

[boscoe99]

The adapter is not required. Yamaha only offers it to try and fool folks into buying stuff they do not need.