Yamaha multi function gauge wiring

[Inthehighlands]

I recently bought a RIB from the UK Lifeboat charity RNLI without engines.

The RNLI heavily modify equipment they use to suit their precise requirements - for example, they modify engines to shut off and waterproof themselves on capsise, so they can be restarted.

I'm trying to work out exactly what they have done to the pair of multi-function taco gauges, which will probably date from around 1998, when the boat was built - although the boat has been serviced several times since. An RNLI service involves TOTALLY stripping the boat down - tubes, deck off! So quite possible the gauges etc will have been updated.....

The gauge has the following wires :
Green/red cut off & sealed
Grey cut off & sealed
White/red cut off & sealed
Blue/white cut off & sealed
Orange blanked off at plug
Black/white taken to a non-Yamaha 3 pin plug
Green/white taken to a non-Yamaha 3 pin plug
Pink taken to a non-Yamaha 3 pin plug
Black battery negative, I believe
Green tacho signal, I believe
Yellow ignition on, I believe
Blue gauge illumination, I believe

I suspect they have disabled various warning lights on the basis they could be distracting in an emergency situation - and because the engines will be maintained to the highest standard.

The boat was originally fitted with Yamaha 75hp engines running on pre-mixed fuel.

I list of which colour wire does what for the tacho would be great! Many thanks in advance.

Inthehighlands

[Inthehighlands]

Nobody knows these wiring colours?!
Andy

[boscoe99]

I recently bought a RIB from the UK Lifeboat charity RNLI without engines.

The RNLI heavily modify equipment they use to suit their precise requirements - for example, they modify engines to shut off and waterproof themselves on capsise, so they can be restarted.

I'm trying to work out exactly what they have done to the pair of multi-function taco gauges, which will probably date from around 1998, when the boat was built - although the boat has been serviced several times since. An RNLI service involves TOTALLY stripping the boat down - tubes, deck off! So quite possible the gauges etc will have been updated.....

The gauge has the following wires :
Green/red cut off & sealed
Grey cut off & sealed
White/red cut off & sealed
Blue/white cut off & sealed
Orange blanked off at plug
Black/white taken to a non-Yamaha 3 pin plug
Green/white taken to a non-Yamaha 3 pin plug
Pink taken to a non-Yamaha 3 pin plug
Black battery negative, I believe
Green tacho signal, I believe
Yellow ignition on, I believe
Blue gauge illumination, I believe

I suspect they have disabled various warning lights on the basis they could be distracting in an emergency situation - and because the engines will be maintained to the highest standard.

The boat was originally fitted with Yamaha 75hp engines running on pre-mixed fuel.

I list of which colour wire does what for the tacho would be great! Many thanks in advance.

Inthehighlands

Learn to fish instead of asking to be fed a fish.

Let me help get you started. Yellow is key on 12 volts to power the instrument. Black is ground. Blue is for 12 volts for the light. Orange is 5 volts output. Green is for the tachometer RPM signal.

Power up the tachometer. Ground first one of the rest of the wires and see what indication is seen on the tachometer. Write it down. Then go on to the next wire. And the next wire. And the next wire.

In no time at all you will have answers to all of your questions.

[Inthehighlands]

If of help to others, this is what I think the wiring does :

Yellow +12V via ignition switch
Black 0V
Green Tacho signal from engine
Green/Red Oil warning (flashes)
White/Red Water in fuel warning
Blue/White Engine maintenance indicator
Green/White Engine overheat (flashes)
Orange 5V output - don't know what would use this
Grey Trim
Pink Trim
Black/White Trim
Blue Instrument illumination

If anyone else is trying to use Yamaha gauges in a non-standard format (eg with a different make of engine etc), v happy to exchange notes!

[fairdeal]

Learn to fish instead of asking to be fed a fish.

Let me help get you started...Orange is 5 volts output...

If of help to others, this is what I think the wiring does :
...
Orange 5V output - don't know what would use this
...

Boscoe - would you elaborate on this particular fish?

for what IS it used?

[99yam40]

My guess is you are asking what the 5V reference voltage is used for with the tach.

Trim needs a reference voltage to be used with the resistance in the trim sender so it knows what position the motor is in

[boscoe99]

There are two wire senders and three wire Yamaha senders. Three wire senders are potentiometers which need a voltage applied to them. The M/F tachometer supplies that voltage.

[fairdeal]

There are two wire senders and three wire Yamaha senders. Three wire senders are potentiometers which need a voltage applied to them. The M/F tachometer supplies that voltage.

Aha - thanks!

But now I am again confused: the OP reported:

Grey Trim
Pink Trim
Black/White Trim

when I saw those, I thought, "ah, I've heard of three-wire trim senders"

But if he is correct - that's a total of 4 wires just to display the trim position?

[boscoe99]

Aha - thanks!

But now I am again confused: the OP reported:

when I saw those, I thought, "ah, I've heard of three-wire trim senders"

But if he is correct - that's a total of 4 wires just to display the trim position?

He is not correct. There is only one trim input wire to the tachometer. It is pink.

[rodbolt17]

and now some curve balls.

Yamaha did make some engines with a 4 wire trim sender,.

now what wires are used on which tach is also going to depend on whether its a two or four stroke.

the gray is an overheat visual indicate.
green red is oil warning,green/white depending on the stroke, is overheat warning or oil level indicate.

green is tach signal,pink is trim indicate.

[Inthehighlands]

Hi Rodbolt

Thanks for your comments.

The boat was built in 1998 and was probably fitted with Yamaha 75 2 stroke engines from the start. But every 4 years RNLI service the boats by stripping them down totally (tubes off, deck off etc), so plenty of opportunity to change things over the years. And the engines & electrics are heavily modified - eg engines being inversion proofed to enable restart after a capsize. There's no "plug & play" about re-engining but plenty of decisions as to what to retain and what to modify.......

I couldn't persuade the grey wire to do anything, whereas earthing green/white causes engine overheat to flash. I'm probably not going to use many of the Yamaha warnings as I'll have a pair of Evinrude systemcheck gauges, but it seemed a good plan to see what might be available.

Thanks to both Boscoe & you re pink - I've been experimenting with a view to using the Yamaha trim function with the Evinrude trim sensors. When/if I achieve something I'm comfortable with, I'll try to write it up.

At some point, I think I'll try to install water separator sensors - I'm trying to work out where the detection electronics are - engine or gauge.

It's interesting - and i'm now at the point of thinking carefully about philosophy - then how to implement it!

Inthehighlands

[boscoe99]

Hi Rodbolt

Thanks for your comments.

The boat was built in 1998 and was probably fitted with Yamaha 75 2 stroke engines from the start. But every 4 years RNLI service the boats by stripping them down totally (tubes off, deck off etc), so plenty of opportunity to change things over the years. And the engines & electrics are heavily modified - eg engines being inversion proofed to enable restart after a capsize. There's no "plug & play" about re-engining but plenty of decisions as to what to retain and what to modify.......

I couldn't persuade the grey wire to do anything, whereas earthing green/white causes engine overheat to flash. I'm probably not going to use many of the Yamaha warnings as I'll have a pair of Evinrude systemcheck gauges, but it seemed a good plan to see what might be available.

Thanks to both Boscoe & you re pink - I've been experimenting with a view to using the Yamaha trim function with the Evinrude trim sensors. When/if I achieve something I'm comfortable with, I'll try to write it up.

At some point, I think I'll try to install water separator sensors - I'm trying to work out where the detection electronics are - engine or gauge.

It's interesting - and i'm now at the point of thinking carefully about philosophy - then how to implement it!

Inthehighlands

The gray wire is for over temperature but only when the tachometer is set up in the two stroke mode. In the four stroke mode then the green wire with the white tracer if for over temperature.

Yamaha offers a sender that attaches to the bottom of a Racor filter bowl. That sensor could be used to trigger the water-in-fuel warning if your motor does not provide it.

Yamaha has and does make many different models. With different features. Since we (I) have not a clue what Yamaha motor you intend to use it is difficult to say what will work and what won't.

Redo your wire test, once in the two stroke mode and once in the four stroke mode. You will seen different functions for different wire colours.

I doubt that an Evinrude sender is going to be compatible with a Yamaha tachometer.

Later model engines and later model tachometers stopped using the engine check light and the water-in-fuel warning. Wire colours have different function across different models. Wire colours change across connectors. Why? Only Yam knows why they do some of the voo doo doo doo they do.