NMEA 2000 info

[ORCA]

I have a 2008 Evenrude 115 with digital guages and a N2K network. Recently, my Lowrance 5200 GPS, which is on the network) and the mph speed readout on the evenrude gauge stopped working properly. I would like to learn more about troubleshooting a N2K system so that I can make my own repairs and additions.
I have replaced the "T" section feeding out to the GPS module, but no change. Also, under system setup for the Bus tells me the antenna is working properly.

I am in hopes that someone with the forum could advise where to find a do it yourself manual for installing and troubleshooting this system? Or, if you have had this same problem, I would love to know how you solved the problem.

thank you in advance.

ORCA

 

[seabob4]

So your "Buss Devices" screen is telling you the GPS antenna is working properly, and you can get a fix. But your I-Command gauge can't see the antenna to get "Speed over ground". Swap your gauge connector to another tee, perhaps your fuel sender, see if this helps. Also, make sure your speed measurement is set correctly...

 

[ORCA]

NEMA 2000 iinfo

Hi Seabob4,

Thanks for your input. I am not able to get a position fix with the Lowrance GPS or the mph readout on the Evenrude gauage. This set-up was installed by the dealer during an engine upgrade and worked for a short period of time. The evenrude equip is under warranty, but I just would like to know how to fix the problem myself. you know the inconvience of trailering and waiting for service at the dealer.

I have tried a new "T" connector for the Lowrance monitor cable with no change in the monitor as far as location my position.

i have not tried to change anything on the gauge menu since this setup did work for a while.

I'm sure it is possible that the Lowrance 5200 has just failed, but why would the evenrude land speed readout fail at the same time????

Any Ideals??

Thanks,

ORCA

 

[seabob4]

As I said earlier, if the "Bus Devices" screen is showing the GPS antenna in the I-Command network to be working correctly, the network is "seeing" the antenna. However, the gauge, and your Lowrrance, are not. Therefore, the issue is in the network, either in another tee, a backbone harness, or whatever.

There are 5 pins on the end of each tee and the middle legs. You can check for continuity with the tees all assembled across each of the 5 pins. 2 of the pins are for power, one pin is for a referance voltage, the other 2 are data transmission. The early "blue" tees and backbones were not as stout as the later "red" ones that replaced them. What do you have?

 

[ORCA]

Hi Seabob2

It has taken this long to complete the troubleshooting and solve the problem with my N2K network. Thanks for your help. It led me to start checking each and every "T" section of the network. Bottom line, the antenna was not working. I happen to have a spare to swap out and yahoo it worked. I also found the dealer had omitted one of the 120ohm resisters on the network backbone. Don't know if this caused the failure, just happy to have my GPS back again. For anyone looking, the Lowrance website has about the best information on a N2K network, for a layman.

Now lets go catch some fish.

ORCA

 

[seabob4]

Orca,
I'm very surprised it worked at all. The Termination resisters are required for the system to work, one at each end of the network. That's weird...

Anyway, glad your on your way...

 

[ORCA]

Hi Seabob4

Yes, I agree and believe some of the conditions I found were mysterious and complicated the troubleshooting. ie, the bus setup mode in the Evenrude instrument gauge, told me the antenna was working properly. Also, the Lowrance GPS module did work for a short time after installation, without the proper resistors in place.

I actually had to take the GPS off the network and connect to a single double "T" with both resistors,to detect the problem with the antenna. Then reconnect the GPS cables to the boat network backbone with proper resistors installed and yahoo, success.

So far, after my first experience with trying to fix a N2K network problem, I don't think the N2K network was designed to minimize cost or simplify installation/maintenance by the do-it-yourself boater.

thanks again for your response and help.

ORCA

 

[seabob4]

Orca,
The NEMA 2000 network greatly simplifies the install at the builder level, but, unfortunately, is very difficult to troubleshoot as there really isn't much you can do but swap out hardware until the trouble goes away, and even then, you have no idea why something crapped out, and what exactly fixed it...

 

[tripp@BOEmarine]

ORCA, it sounds like you got it pretty well figured out, but this is also a great resource that is not brand-specific.

http://www.boemarine.com/Support/Articl ... D559FA2AFC

Tripp@BOEmarine