Old control box on newer F50ltr

[Walknbob]

I am swapping motors on our 16' Alumaweld. I recently purchased an older but unused Yamaha control box part # 703-28199-32. I did not realize until I received it how old it was... 1989. I am planning to use it on a 2005 Yamaha F50ltr. I can see that the tach and other connectors are not the same. I am not sure about the ignition etc that plugs into the motor itself. My questions are
1. Is this going to work at all?
2. based on reading other posts here is there some kind of wiring adapter going to be necessary.
3. is there an online manual or other video etc that can help me through this?

Thanks

[Walknbob]

re: older control

If no one here can answer this could anyone suggest were else to look?

Thanks

[99yam40]

I have no idea, but Boscoe99 might come up with the answer

[boscoe99]

I am swapping motors on our 16' Alumaweld. I recently purchased an older but unused Yamaha control box part # 703-28199-32. I did not realize until I received it how old it was... 1989. I am planning to use it on a 2005 Yamaha F50ltr. I can see that the tach and other connectors are not the same. I am not sure about the ignition etc that plugs into the motor itself. My questions are
1. Is this going to work at all?
2. based on reading other posts here is there some kind of wiring adapter going to be necessary.
3. is there an online manual or other video etc that can help me through this?

Thanks

The control box should plug and play. As long as it is the ten pin type. Count the number of terminals in the connector at the end of the harness. There will be ten or seven. If you count ten you got lucky.

What type of tachometer do you have? Need to see a photo of the connectors at the end of it. It might be a two stroke only type is from 1989.

A 2005 Yam will be an F50TLRD by the way.

[Walknbob]

Thanks for your reply! The connector is a 10 pin. I would have to check the model #on the motor but it is down at our storage area so I will have to check tomorrow. Its a 50 hp 4 stroke EFI...

Here are two images... one is the new (old) harness the other is the tach and ampmeter currently attached to the Yamaha motor

[99yam40]

are you sure it is an ampmeter?
my guess is these are not Yamaha gauges

[boscoe99]

Those look like Teleflex gauges.

That motor, and you, deserve a newer Yamaha multi-function tachometer. You can pick them up some times quite cheaply on Ebay. The tachometer also provides normal useful information but it will also tell you want the warning horn is about, if and when said horn blows.

Is that an F50TLRD or an F50TLR? Makes a difference. What I want you to do is to look in the engine pan and see how many ivory coloured nylon connectors there are? One or two please?

[Walknbob]

are you sure it is an ampmeter?
my guess is these are not Yamaha gauges

I suspect you are right about the gauges.

[Walknbob]

Those look like Teleflex gauges.

That motor, and you, deserve a newer Yamaha multi-function tachometer. You can pick them up some times quite cheaply on Ebay. The tachometer also provides normal useful information but it will also tell you want the warning horn is about, if and when said horn blows.

Is that an F50TLRD or an F50TLR? Makes a difference. What I want you to do is to look in the engine pan and see how many ivory coloured nylon connectors there are? One or two please?

Hi 99yam40

There is only one plug in the engine pan. I have included a pic of the model tag and as for the guages in an earlier pic. one is a tach and the other volt.

[boscoe99]

Here is the way it would be wired to Yamaha gauges.

[Walknbob]

Ok.... I see what you're saying but I don't see how this schematic coincides with the one I showed in the earlier pic I provided of what I have on the controls I have. If I am understanding this the 10 pin connector will allow the ignition and trim to work. I am guessing the single nylon connection in the pan allows a tach and some other gauges to work. But I don't understand how to convert the 3 wire groups from the "new" control to connect to a tach etc. If that makes sense....

[boscoe99]

The tachometer you have requires voltage, a ground and a tachometer signal. The control box provides that in the form of the yellow wire, the black wire and the green wire. In the case of the Yamaha there is a small harness that connects between the control box and the gauge(s). The small harness also provides voltage and a ground for the tachometer light.

The motor requires voltage for the starter motor, voltage for the ECU, voltage for the trim and tilt, a ground for the voltages and a ground to stop the motor. The control box provides all of that in the ten pin harness.

If you don't use a Yamaha tachometer then you need not be concerned with connecting a harness to the output connector that is located in the engine pan. If and when the warning horn sounds you simply will not know specifically why it is sounding.

[Walknbob]

The tachometer you have requires voltage, a ground and a tachometer signal. The control box provides that in the form of the yellow wire, the black wire and the green wire. In the case of the Yamaha there is a small harness that connects between the control box and the gauge(s). The small harness also provides voltage and a ground for the tachometer light.

The motor requires voltage for the starter motor, voltage for the ECU, voltage for the trim and tilt, a ground for the voltages and a ground to stop the motor. The control box provides all of that in the ten pin harness.

If you don't use a Yamaha tachometer then you need not be concerned with connecting a harness to the output connector that is located in the engine pan. If and when the warning horn sounds you simply will not know specifically why it is sounding.

OK let me see if I am understanding. Of the three groups of wires from the con*****er I have recently purchased the group of green, yellow, and black will operate the teleflex tach I currently have... is that correct? If so I could start from there and add additional / newer gauges to this wire set as I acquire them? Because if that is the case I will be glad to work from there. We ran out again today with the old Merc (98, carb 4 srtoke) and I am not happy with its performance near the mouth of the river especially when the tide turns to ebb (Siletz River, OR).

[boscoe99]

OK let me see if I am understanding. Of the three groups of wires from the con*****er I have recently purchased the group of green, yellow, and black will operate the teleflex tach I currently have... is that correct? Yes. See the diagram. Yellow, black and green go the the gauges. At least in the image I am seeing they do. If so I could start from there and add additional / newer gauges to this wire set as I acquire them? Because if that is the case I will be glad to work from there. We ran out again today with the old Merc (98, carb 4 srtoke) and I am not happy with its performance near the mouth of the river especially when the tide turns to ebb (Siletz River, OR).

Comments added.

[Walknbob]

Comments added.

Thanks Boscoe99
I appreciate your information and advice. I hope to do this swap this week. I hope it goes well... I'll let you know and hopefully wont have to bug you with anymore requests;