Yamaha Multifunction Tach 6Y5-8350T

[SlayerT123]

Hi All,

Just wondering if anyone can help. I have been given a Multifunctioning Gauge (6y5-8350T not sure if this is a -90 or -82, -83) but I'm not sure how to wire it to my Yamaha 1997 2 Stroke 40VETO.

I've heard there are 2 types of gauges, one for older than 2004 and another which if for 2005 or newer. I believe I have the one for newer models as the person had a 2015 F40LA but I could be wrong.

Does anyone know what extra wiring harnesses I'll need and the part numbers? The gauge appears to have 8 wires, 4 of which are attached to a plug, while the other 4 are free. Do they just connect to the Control box (I have a 703-48207).

Also I'm having trouble locating the Trim & Oil plugs from the engine, are these easy to locate?

Any wiring diagrams and advice would be greatly appreciated.

Thanks,
Tom

[Jason2tpa]

The pdf link below is the best all-inclusive tach/speed instructions I've come across. All necessary gauge components are listed with part numbers, as well as instructions for installation.

http://www.mbcboats.com/perfbull/Yam...KitInstall.pdf

Follow the A, B, and C for locations for the engine side oil and trim harnesses

[boscoe99]

A 40VETO should be the equivalent of a USA 40TLRV. If you have power trim and tilt and an oil injection system. Parts and diagrams can be found here.
1997 40TLRV Yamaha Outboard Parts

You have a -90 tachometer. Intended for 2005 and later Yamaha's that have a two wire trim sender and single trim/oil connector.

The -90 tachometer has a trim gauge embedded within. Which is not usable on your motor being that it uses a three wire trim sender.

For the over temperature function and the low oil warning functions to work you are going to have to string some wires. Possibly cut and splice. What do you want to do?

The actual tachometer indication function will be relatively easy. A green wire in the ten pin harness to the control box connects to a fused harness that provides power, ground and the tachometer signal to the gauge. It looks something like this:

[SlayerT123]

Thanks guys for your responses. Much appreciated.

Boscoe, would the Trim work if I purchased an adapter harness (2plug to 1 plug) 6Y5-85335-10 along with the Trim and Oil Harness 68F-82553-XX-00 (pic attached).

I was planning on getting the above harnesses along with the 6Y5-83553-M0 (Will the harness with single fuse be sufficient, or will I need the dual fuse harness?)

I don't mind trying to wire up my own harness, but if it's a complex job, I would rather just purchase the required harnesses.

Thanks.
Tom

[boscoe99]

The three wire sender on your motor uses a potentiometer. That potentiometer is normally provided 5 volts by different style Yamaha tachometers. The -90 tachometer does not provide the five volts needed by the sender.

A craft person might be able to buy a 12 volt to 5 volt regulator and use that as a means to provide the sender with the necessary voltage.

https://www.ebay.com/i/131199957529?chn=ps&dispItem=1

[SlayerT123]

Thanks Boscoe,

I'll see how I go this weekend and update.

[SlayerT123]

Hi Boscoe,

I managed to fit the adapter harness 6Y5-85335-10-00, and the trim appears to work correctly after switching the dip switches to Off, On, Off. Only thing I'm worried about is the temperature icon. It constantly flashes when the key is on. I disconnected the grey wire on the harness, and it now stops flashing, however does that mean that the oil and temperature warning signals and audible sound won't work now? Is there a way I can test that the warning sounds will still work? I'm assuming that the sound will now come from the 703 control.

Sorry for the late reply, but I only managed to get the parts and install last weekend.

Thanks,
Tom

[boscoe99]

Does the 40VETO model that you have use premix or does it have an oil injection system?

[holmen78]

The O in 40VETO means it has oil injection. T is power Trim. E is electric start.

[boscoe99]

The 40VETO was not sold here in the USA. We have limited information regarding what the various letters mean for non-USA models. VETO basically means nothing to us here.

Now another question. Does your model use a single warning lamp at the front, three warning lamps or no lamps? Reason why I ask is because the service manual depicts 4 different configurations. Trying to figure out which specific configuration your motor uses. It makes a difference as to wiring from the motor to the gauge.

[boscoe99]

Hi Boscoe,

I managed to fit the adapter harness 6Y5-85335-10-00, and the trim appears to work correctly after switching the dip switches to Off, On, Off. Only thing I'm worried about is the temperature icon. It constantly flashes when the key is on. I disconnected the grey wire on the harness, and it now stops flashing, however does that mean that the oil and temperature warning signals and audible sound won't work now? Is there a way I can test that the warning sounds will still work? I'm assuming that the sound will now come from the 703 control.

Sorry for the late reply, but I only managed to get the parts and install last weekend.

Thanks,
Tom

Pull the kill switch so the motor will not start. Engage the starter switch. The alarm buzzer should sound.

The buzzer is embedded within the control box.

The wires for the over temperature ground and low oil quantity ground go the to tachometer for the visual indications only.

Adapter harness will not be used. That is for models that have two trim/oil plugs connected to the main engine harness. Your model may have no plug or only one plug.

[SlayerT123]

My motor has 3 lamps infront. I will test the alarm buzzer tonight and let you know how I go. Originally when I was looking for the plugs in the engine, I found 1 free plug (4 female pins with pink,orange,blk,grey) and another plug which was already connected, which I assume was the 2nd plug which I disconnected and connected to the extension harness which had 2 plugs on each end. When I attached the adapter harness to the extension, that left just 1 plug which connects to the MFT.

Would you recommend that I install a Water Temp gauge and Water Pressure gauge to be on the safe side. Can aftermarket gauges and sensors be used? Or should I start a new thread for this.

[SlayerT123]

I've noticed that the Gauge plug does not have the orange and black wires. Anyone know if they are required. On the older version MFT gauges I noticed they have 2 plugs, which have additional wires connected to the plugs. 1 has extra red/white and blue/white wires, and the other plug extra Orange and black/white wires. I assume the adapter harness disregards these, and are possibly not used. Does anyone know if those extra wires are required?

[boscoe99]

I would string a wire from the pink wire in the engine harness to the gray lead on the tachometer. This will cause the over temperature icon to flash in the event of an over temperature event.

You can either disconnect the warning lamp module at the front of the motor or tap into it so that the grounds to the module can be applied to the tachometer.

The green lead connects to green/white lead on the tachometer. This will allow the tachometer to indicate full oil with the tank is full (three bars will be shown) and to indicate when the tank is not full (right bar disappears and middle bar flashes).

The green/red lead connects to the green/red wire on the tachometer. This will cause the middle bar to disappear and the left hand bar to flash when the tank is low on oil. At that time the horn should sound and the motor should go into RPM reduction mode.

[boscoe99]

I've noticed that the Gauge plug does not have the orange and black wires. Anyone know if they are required. On the older version MFT gauges I noticed they have 2 plugs, which have additional wires connected to the plugs. 1 has extra red/white and blue/white wires, and the other plug extra Orange and black/white wires. I assume the adapter harness disregards these, and are possibly not used. Does anyone know if those extra wires are required?

Older tachometers and some older engines used the orange wire for five volts to a three wire trim sender and the black wire for ground.

The red/white wire in the two connector tachometer was for water in fuel warning as I recall. The blue/white wire was for the check engine warning.

All that has been done before does not really apply to your specific model. You are attempting to use a tachometer that was not intended to be used with your model.