2003 225 Optimax rigging connections.

[Nasher]

I've been having a good look over the 225 Opti I've just purchased trying to familiarise myself with what goes where.

It doesn't help that the engine is currently laying on it's back on a pallet and it's not easy to see all of it.

I'm happy with the main 8 pin wiring harness plug and 4 single wires.
Also the Gear and Throttle controls.

But I have some questions that I can't find answers to in the installation part of the manual I have.

Easy one first.
This cable looks like an old accessory cable to me.
The plug end was coiled up in the tray, the other end was just cut off down by the saddle.
Can I assume it's for an old accessory??



Next I found this cable coiled up in the tray.



It has a label on it with part number 84-85924, which from a quick google appears to be something to do with the smartcraft gauge/system.

But the smartcraft cable I've been supplied with is the Blue one here and both ends have the connector shown with the purple inside.
The two are not compatible.



The smartcraft gauge has a socket on the back compatible with the Blue cable.
Have I been given an incorrect type of smartcraft cable, or does the Blue cable connect somewhere else on the engine?
If the Blue cable is correct, what's the 84-85924 cable for?

Then I tried to figure out where to connect the battery cables to.

I found this loose nut on what looks like a solenoid.



Could that be the +ve battery cable connection?

I also found a bolt on connection point on the starter motor solenoid that looks like a cable has been removed,



But it doesn't make sense that it's the -ve battery cable connection as I'd have thought that would be through the block.
So where do I connect the -ve battery cable?

Also I've found this cut off heavy cable.



The other end is connected to whatever this is at the top of the engine.



I'm a little annoyed about this one as it's obviously supposed to be connected to something, and having been cut off I'm going to have to make a new one.

Can anyone shed some light on any of the above?

Thanks

Nasher.

 

[Nasher]

I've been sent some wiring diagrams that have give me a much better understanding of what's going on.

My issue stems from the fact that the engines were supplied from the factory with a standard length set of Battery Cables already attached to the engine under the hood, so the installation guide only details how to attach the cables to a battery, it does not need to show where they attach to the engine.

Plus the detail drawings in the installation guide do not bear any resemblance to my engine.

From the wiring diagram I've snipped this:


It's shown me where the +ve battery cable should be connected, ie at the starter motor solenoid item 25.
On my engine it's obvious it was never connected there as there is no witness marks, instead it was connected at the bottom of the slave Solenoid item 23.

More worryingly it shows that the cable that's been cut on my engine is the main charging feed from the Alternator. That would have been great having the bare end of that floating around the engine when I first started it!
I'll be talking to the dealer about it.

What I still need to know is where to attach the end of the -ve battery cable to the engine. I just can't find where it's been unbolted from, so if anyone knows, or can look on their engine I'd really appreciate your help.

Whilst digging around I did find this:


It's the connector for the Blue Smartcraft cable to plug into, so that's now sorted.
But of course that still leaves the question of what is the 84-85924 cable for?

The other end of it is connected to the main harness here:


Again if anyone can help I'd appreciate it, but am going to pour over the wiring diagram shortly to see if I can match up the colours of the cables.

I've got some other questions, but will leave them until I've been able to check what I can find in the diagrams.

Nasher.

 

[Nasher]

It looks like the 84-85924 cable is plugged in here:


Described as
41. SmartCraft boat sensor harness connection.

So I'm assuming I can just leave it disconnected?
Or remove it completely to keep it out of the way?

Thanks

Nasher

 

[Frenchbruno]

A)your first picture on the top of the thread is the connector to the optional paddle wheel, you are not in obligation to connect it. Just inform the smart craft the speed info comes form another device like pitot tube or gps. Not very complicated.

B)For your motor starter perhaps the previous owner have installed a starter from another generation like year 2000. For the year you've the wiring drawing is fine. be careful wheel installing the negative battery cable on the block behind the starter, it's easy to squeeze a oil line coming out from the oil pump, an kill your engine very fast.

C) The big red cable is coming from the alternator and the yellow translucid part crimped in the middle is a 100 amp Fuse ,#26 on your drawing

D) for the 84-85924, this cable is located on the starboard side of the engine in the lower cowlings, and is connected to the different plugs located on the same side
good luck

 

[Nasher]

Thanks Bruno.

I don't need Speed to be shown on the Smartcraft Gauge as I use the speed on my Chartplotter. I'll just remove the Paddlewheel cable.
It has been roughly cut off by the saddle anyway, so is useless as the sensor end is potted into the sender unit.

The starter motor is correct to the wiring diagram so i assume it's correct for the motor. It just doesn't match the drawings in the manual.
From your post you are suggesting the Battery -ve cable is attached behind the starter motor, I'll have another look - does anyone have an image showing where?

Yes as mentioned I've found out what the cut-off big red cable is, and am not happy.
Cutting that off and tucking at away so it can't be seen could have caused a fire or shorted all the electrics out when I first started the engine.
Also I can't just make another one, I have the correct crimp tools to make the cable, but need to find a way to add the 100A fuse.

I don't know what the 84-85924 cable is for, I found both ends as pictured, but think I can just leave it disconnected.

Nasher.

 

[Frenchbruno]

84-85924 location on the engine , see picture (250xs here)

for the starter there is 2 types of wiring, before year 2002 and after see picture for september 2003 year engine (250 xs here)

 

[Nasher]

Thanks Bruno.

the images are useful. I can see what I need to see.

I know where the 84-85924 cable is, I've photographed it and posted it above.

But do need to know what it is for?

Thnks

Nasher.

 

[Frenchbruno]

84-85924 cable collect informations from accessories, like paddle wheel, oil tank, fuel tank, and send the signals to the smartcraft system

 

[driver510]

Mercury optimax

Hi call me on 07702958175 I live in Portsmouth rsoutboards I can let you know what goes where ?

 

[Nasher]

Thanks will call tomorrow.

I've got a better understanding from internet research how the system works, and have realised that I've got a Smartcraft Speedo when what I want is a Tacho.
Should have looked at it better when it arrived.
Would also like a system link temp gauge, but realise I need to install a hub etc for that.

Plus I now believe that I will get a constant alarm if there is no trim data fed to the system, so I need to find a way to connect the accessory cable under the hood into the system. The trim sender is connected to the accessory harness but that harness is not connected to anything.

Also need to know if I will get an alarm or the system will throw a wobbler if there is no speed data input to the system.
I don't want or need to know the speed, I have a Chartplotter, and don't want to install the Smartcraft speedo.
But anyway both speed data inputs on the engine are Fubar.
The paddle wheel is missing with the cable cut off at the saddle, and the Pitot tube has also been cut off at the saddle. Plus the Pitot tube sensor cable is connected into the accessory harness which as above isn't connected to anything else.

Nasher.