Brought to you by Barnacle Bill's Marine Supply. (856) 785 9455

Sign up Latest Topics

  Author   Comment  

Posts: 2
Reply with quote  #1 

Hi All, I am a brand new Evinrude owner, and super excited. Just used my new ETEC 150 this past weekend and have been thrilled with the motor and performance so far. I am having a bit of trouble with my NMEA network, and was hoping I could find some help here (this site is fantastic, I have found so much helpful information already on other topics). I have searched this topic as well, and there is a lot of information, but I haven't been able to solve quite yet. 

I previously had a NMEA 2000 network that consisted of my Suzuki motor, Motor gauge, SIMRAD GO9, Fuel Data Storage, and Fusion unit. 

My wiring harness for the Evinrude had P/N 764159 included which was attached to the ICON Pro gauge and had a NMEA plug in. I do not have ICON electronic controls, therefore, there is no Gateway module included. 

I have included in my network a Garmin Power Isolator. On one side I have power set up from P/N 764159 and have my ICON Pro Guage, and the EMM from the motor. On the other side of the power isolator, I have my SIMRAD GO9, the Fusion, and the fuel data storage. 

My gauge would power on (when the key turned) and would display engine data. The SIMRAD can see the fuel data storage and the Fusion unit, but did not receive data from the EMM (no rpms, temp, etc). 

I moved the EMM network cable to the other side of the power isolator, and at that point the SIMRAD showed information from the EMM, Fusion, and fuel data. However, the ICON guage did not receive any information (read "NO DATA"). 

It seems that information is not passing through the Garmin Power Isolator like I hoped it would. The two backbones are connected via a drop cable/network cord and not directly in-line. I have read there could be issues with that cord, or possibly issues from the two power sources being different (1 side being the starting battery and the other the house system). 

I am pretty stuck, any help you guys may have would be greatly appreciated! Thanks!


Attached Images
Click image for larger version - Name: Screen Shot 2019-05-20 at 9.36.12 AM.png, Views: 12, Size: 111.91 KB 


Posts: 2,492
Reply with quote  #2 
Two thoughts to get started.
I think all network devices need to have the same ground source.
Don't think you have any need for a fuel data module.

Posts: 6,388
Reply with quote  #3 
In general there is no need for a network power isolator in a simple network. 

Does your network have two power nodes? 

It sounds like there is only one power node, and with an isolator in the wiring, half the network does not have network bus power.

Also, usually the data storage module MUST be on the same network power as the E-TEC engine, and ANY TIME the Data Storage Module is getting power the E-TEC engine ignition key switch should be in the RUN position.

That is why in the E-TEC wiring they ALWAYS show the network power coming from the ignition key switch.

If the data storage module gets power and can't find the E-TEC on the network, it goes haywire. 

I recommend:

--remove the network power isolator gizmo (but be certain there is only one power node to the network)

--wire the network power node so it gets power from the ACCY circuit of the E-TEC ignition key switch

EV-Diagnostic cables are back in stock.


Posts: 2
Reply with quote  #4 

Jim, thanks for the response. 

I was under the assumption it had two power sources, one from the original NMEA starter kit (wired to the house battery) which it definitely does, and then the other being the P/N 764159 related to the ICON Pro Guage. Let me know if the P/N 764159 is not providing power. 

Like others, I want to be able to use my SIMRAD's networking/display functions WITHOUT having to have the key switch turned out, hence my decision to put the power isolator in. My SIMRAD unit is the headunit of my fusion stereo, and I dont want to have to have the key on while listening to music while on the sandbar. 

Let me know if you or any others have any thoughts to this. 



Posts: 2,492
Reply with quote  #5 
Your setup sounds correct and connected properly for a "key on/engine, gauge" network on one backbone and an"always on" backbone on the other side. It is very likely that your backbone cable or power isolator T is not passing data.
Try connecting the Simrad on the engine backbone.
If the Simrad and Icon pro show engine data then next chance the cable connecting the two backbones. The cable connecting the backbones should be connected to the end of the T on one end and the end of the power isolator on the other end.
There should only be a total of two terminating resistors in the entire system.

Posts: 6,388
Reply with quote  #6 
MICHAEL--thanks for further elaboration on the power wiring to your NMEA-2000 network, and that you want to be able to use some devices on the network without having to put the ignition key of the E-TEC in the RUN position. Your reluctance to do that is quite understandable; I share that same reluctance.

To investigate if the CAUSE of the problem you are presently having is due to a defect in the POWER ISOLATOR, you can easily check that device to establish if there is CONTINUITY the DATA and SHIELD circuits through the device,  and there is NO continuity between the contacts that carry power. through the device. For help in identification of which contacts in a NMEA-2000 DeviceNET Micro C connector, see my article at


The drawings with views of the contact locations in the connector body and clear identification of the signals they carry will be useful for you in checking the power isolator. Each contact should only have continuity to its associated contact on the other side of the isolator, except the power contacts which should have no continuity to any other contact, even the associated other power contact.

After you carefully check the continuity through the power isolator, you will know if the power isolator is the cause of the problem or not. Let us know the outcome of your checks. If the power isolator is not the cause, we will have to scratch our heads some more.


I recommend--based on my own extensive experience--that you configure the network power segments so that an isolated segment is fed power from the ACCY contact of the E-TEC ignition key switch, and that on this segment you connect the E-TEC engine, and the FUEL DATA MANAGER module also called the DATA STORE MODULE or the MEMORY MODULE. 

On the other network segment you should provide network power in any manner you like, but I do not recommend using an ALWAYS-ON direct connection to 12-Volt battery power. On this segment of the network you should connect your SIMRAD multi-function display and your entertainment device control panel. 

Also, when you had a SUZUKI engine, the equivalent of the FUEL DATA MANAGER module was provided in the NMEA-2000 adaptor cable that connected the SUZUKI engine to the NMEA-2000 network. For some reason, SUZUKI required that arrangement for the cable that Lowrance (NAVICO) was selling. Perhaps it was in recognition that for the device to work properly, it MUST be on the same branch of the network as the engine and get power only when the engine had power.

FINALLY, if you do find the power isolator is defective, you might consider completely changing the power wiring on the network to use a power inserting T-connector that is wired with two isolated power circuits, one for each side of the network backbone. This will simplify your network wiring. MARETRON makes such a power inserting device. See

Micro/Mid Powertap Tee

If you do select that power inserting T, note that both ends are configured with socket contacts. This is intentional in order to prevent power from appearing on pin 
contacts. If you use the MARETRON MICRO POWERTAP, you will have to get a new 120-Ohm terminator for one end of your network, a terminator with pins instead of sockets.

You will then have two leftover power inserting T's. Keep one for your bench network for NMEA-2000 testing and use of network devices away from the boat, and sell the other.

EV-Diagnostic cables are back in stock.


Posts: 6,388
Reply with quote  #7 
Originally Posted by madicks2_or_MICHAEL
Let me know if the P/N 764159 is not providing power.

There are two problems for me to reply.

First, I don't know what PN 764159 refers to.

Second, I don't know how you have installed it.

From the image, PN 764159 looks like a network T power node that can be fed from two SOURCES.  This part was probably intended to be used with TWIN engine installations and each one of the two power leads would be wired to one engine's ACCY circuit. This would allow the network to have power if either engine had its ignition key switch in RUN. 

You really do not need that function because I believe you only have one engine.

I cannot tell how you have wired the device so I don't have any way to know if it is providing network power or not.

EV-Diagnostic cables are back in stock.

Previous Topic | Next Topic

Quick Navigation:

Easily create a Forum Website with Website Toolbox.

Disclaimer: Activities and modifications described or displayed on this message board and it's pages may be potentially dangerous. E-TEC Owners Group along with Barnacle Bills Marine does not endorse or make any claims to their safety or performance. Be sure a trained E-TEC service technician performs all your service work.