SmartCraft: Help needed!!

W812 · Apr 26, 2025

I need some help from someone with more knowledge about this system. I have purchased a new(ish) outboard. It’s a 2023 mercury 60 4 stroke. It has the 14 pin connection for the main harness on the engine. I was given a harness with ignition switch. The harness is not as new as the motor. I believe it’s dated 2012-13. We also purchased online a smartcraft gauge level 1 to handle our instrumentation we need. I have gotten a male to male connector to plug into the harness so I can connect to the gauge itself. Nothing happens. Now, I can plug the gauge directly to the back of the motor with the harness that came with the instrument and it works fine. Am I missing something or what am I doing wrong??

alldodge · Apr 26, 2025

Welcome
You need most likely a hub, terminator and other cables

Smartcraft uses the 10 pin CAN connector

Post pic of gauge you have

W812 · Apr 26, 2025

79-8M0135536 NMEA 2000 Data Level 1 Kit SmartCraft MercMonitor - No NMEA 2000 Data

This is the description of what we ordered with part number. I will attach pic of the gauge itself.

W812 · Apr 26, 2025

The gauge also came with its own harness part number on that is 84-8M0055076. It plugs into the instrument and has some other connections on it as well. It would not plug into the original engine harness however. So I got a male to male connector to go from the engine harness to the gauge harness. No dice. If I plug the gauge and it’s harness directly into the engine(plug next to the 14 pin harness connector round plug) it comes on and works fine.

alldodge · Apr 27, 2025

ok, you need to connect it as show below
Look at the part listing needed to do so

W812 · Apr 27, 2025

Okay so according to that you are saying I need a junction box and a terminating resistor to put on the box. Then plug my instrument and its harness to the j box. Just trying to understand the system more, how does this make it work exactly? Is it the resistor that does it? I have a male to male plug which I’m using in place of the box currently to make the connection between the two harnesses. How does it work when I plug directly from gauge and it’s harness to the back of the engine on the plug there but not how I’ve been doing it?

W812 · Apr 27, 2025

W812 said:
Okay so according to that you are saying I need a junction box and a terminating resistor to put on the box. Then plug my instrument and its harness to the j box. Just trying to understand the system more, how does this make it work exactly? Is it the resistor that does it? I have a male to male plug which I’m using in place of the box currently to make the connection between the two harnesses. How does it work when I plug directly from gauge and it’s harness to the back of the engine on the plug there but not how I’ve been doing it?

Or are you saying I need to be using an additional harness off of the back of the engine and not use the connection on the 14 pin round main harness? In which case I would need that harness in the length I need and a jbox and another resistor

alldodge · Apr 27, 2025

You need wiring harness "a"
1 - J box
1 - terminator 'b"
1 - weather caps 859318T2

Pic is older style monitor

W812 · Apr 27, 2025

Okay last question. On the main engine harness it has a plug presumably for this application. Why am I unable to use it?

alldodge · Apr 27, 2025

W812 said:
Okay last question. On the main engine harness it has a plug presumably for this application. Why am I unable to use it?

Which plug?
Could be because it should be connected to SC harness

Here is a thread where the guy went through the full install
https://forums.iboats.com/threads/how-to-install-a-smartcraft-system.265777/

W812 · Apr 27, 2025

84-896537A20 is the main engine harness. Has the key switch and all. It has one of the 10 pin plugs on it which I was under the impression was for a gauge like this.

alldodge · Apr 27, 2025

The 10 pin connector is a CAN connection used to connect diagnostic scanner to like Merc G3 dealer or Rinda which all can buy

W812 · Apr 27, 2025

Okay I understand. So I cannot plug into that and expect my gauge to work. My engine has wheat appears to be a resistor in the cap on the plug for this new harness I need to order. Am I able to retain that and use it on the junction box I need instead of ordering an additional one or are they different?

W812 · Apr 27, 2025

This is where I get confused. Reading this document it seems like I should be able to do what I’m trying to do. Which is use the 14 pin harness and the 10 pin connector on that harness to go to my gauge via a jumper instead of a junction box.

https://www.mercruiserparts.com/Attachment/DownloadFile?downloadId=42&srsltid=AfmBOorEsi5kFcOpYVzqYX8aCv5I7cSlfDAgpUr0AHmgziiMEJXd9GWH

alldodge · Apr 27, 2025

Most install using a J-box, and the reason is if something goes wrong and you need to scan for codes you only need to remove the dust cap on the box to read.

If you don't use a J-box and just use a 10 pin cable from the motor then you need a resistor 10 pin CAN connector and just connect Gauge to other end at helm, no termination resistor needed

If you have a harness which connects to the 14 pin harness and also has the 10 pin connector at the helm then you don't need to use the 10 pin connector at the motor. You do need to have the termination resistor on the motors 10 pin. The 2 pin CAN P connector has to have a 2 pin termination resistor on it.

This should help

W812 · Apr 27, 2025

Yes that’s what I thought. I have those things and it still won’t work. Unfortunately the cheaper option seems to be getting the secondary cable and J box.

SmartCraft: Help needed!!

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