Sunday, April 15, 2012

Engine NMEA 2000 crap

"Really, that's all I need, just the gateway kit, how much is it? Ouch $250 bucks? Well it is what it is, I guess, and the owner wants to see his engine instruments on his chart plotter." Fast forwarding a week UPS delivers me a box, and I go to the boat. Avidly ripping open the box, I behold the kit before me. There it is in all its glory, a small black box with an LED, and two cables coming out of it. Yep, one of them has a standard NMEA connector, and the other one has a what? It's a nine pin female connector, where the heck does this thing plug into? Wait a minute, it's a kit remember, and in the bottom of the box is another cable, with a nine pin male connector. I plug it in, and then look closely at the other end. Hmmm, it's a male 4 pin connector. Whats this plug into? I can see the entire engine harness, the engine gauges, the control computer, and the device bus, and nowhere is there someplace this four pin connector can go. Rats!

I call the engine builder's tech support department. "What's up with this kit? I can't plug this into anything, and I know what it's supposed to be plugged into. It's not going to fit without a saw." "Well you must have bought the wrong kit then, because if it was the right kit, it would plug in." "Sorry, but I want to politely disagree, the instructions specifically say it's for this exact engine configuration." "Maybe you should just take your boat to a certified dealer, they have been trained to do this sort of technical work." "Listen, it shouldn't require a $100 per hour technician to push in one plug, something must be missing from this kit I need to make it work." "Okay, let me check with someone, hold please. Okay, we don't get a lot of calls about this, but you need another cable." "Another cable? What does that do?' "Well it plugs into the pigtail in the kit that was plugged into the cable from the gateway, and then that cable plugs into the bus." "We sell them separately because we don't know what length you will need." "Okay, but why don't you just put the right bus connector on the gateway cable in the first place, and if you need more cable, sell extension cables that plug into that?" "I don't know I just work here, a 6' cable is $80.00, here is the part number." Okay thank you very much, I will order it from a dealer."

It's "Tin Hat" paranoia time now. You can tell I'm a little miffed (that's not me in the pic) about all of this. A NMEA interface should be a straight forward thing, but in all too many cases it is mired in a collection of expensive bits and pieces that are poorly documented. Manufacturers take standard device communication protocols that are well known, and then twist them around so others can't use them, without being sued at any rate. They then design expensive "Gateways" to let you get at the data, often requiring special cables only made by them. Add to that manufacturers who take standard NMEA 2000 network cabling components, and redesign them so you have to use theirs only, and to interface to a standard network, you have to buy their special adapters, and don't get me started on the costs of all of these pieces.

As an example, since when is this cable really worth $120? Seriously, you gotta be kidding me, a NMEA connector on one end, and a Yamaha bus connector on the other. But when it's only made by one company, the sky must be the limit. I should really be in the cable business.

I can't tell you how many hours I have spent trying to get all of the right parts to do an engine interface. Yes I'm smarter now, but only with one scenario, and I don't really know whether this one will work yet. We will find out next week when I get the cable that plugs into the pigtail, that plugs into the cable that is attached to the little black box. What's so frustrating is that so few engine manufacturers post any real information online, and their tech support departments can be vague also. Unfortunately more than a few dealers are clueless, and the online forums are rife with out of date information and part numbers.

Yamaha - Command Link Plus gateway about $250 + extension cable starting at about $80. The original Command Link  gateway is similar, and I don't know if the single cable still works, or you now have to buy the gateway.
Mercury - (Merc Monitor gateway) for up to 4 engines $900. It appears to be a complete kit. A pricing ouch, but you do get a pretty gauge with it.
Honda - No gateway required, cable only starting at $70.00.
Suzuki - No gateway required, cable only about $100.
Yanmar - Newer engines standard NMEA 2000 cable only.
Cummins - Could never figure it out, and neither could the Cummins' people I spoke to.
Volvo - No pricing on their online store website, and none found online.

Regardless how the engine companies choose to package, price, and sell the NMEA 2000 interface, it would be nice for all of them to clearly spell out how it's done, and what you need to do it. It would really be better for all if you engine dudes just simplified, and made the NMEA 2000 interface standard. Some of you get it, some don't. I'm taking the aluminum hat off now, and pouring a glass of whine.


  1. No tin foil hat needed. Despite trumpeting the benefits of "NMEA 2000" the electronics makers are being dragged kicking and screaming into the standard. Especially the hardware standard.

    "Brand X: Yeah we are N2K compliant. Standard connectors? Um. No. You will need to buy an adapter to interface with Brand Y."

    Standard my ass. Anything to lock you into their brand. Otherwise you must pay an installer to buy an overpriced adaptor and install it with minimal support resources in order to get what you want. Once they have your money for the main units, they don't care to make it easier for the user (or installer for that matter).


  2. If it is a Cummins engine with a smartcraft system. The J1939 data can be found on pins g(data high) and H (data low) on the rectangular purple faced plugs on the smart craft harness "HUB". Oh yeah get out your magnifying glass to find the g and h on the connector. If you connect these to the J1939 side of a gateway (we use the maretron J2K-100) you will get engine data on your N2K network. we figured this out a couple of years ago and now I periodically get calls from people who say that the local cummins dealer referred them to us because they don't know how to do it. The best part is that they are the ones who told me.

  3. What ever happened to the K.I.S.S. method. I just repowered with a new 150 Yamaha. So far I have spent about a month waiting on these stupid cables and every time 1 comes in I get another call from the mechanic telling me "by the way, you need this other POS to make the 1st thing work. And it is ba kordered" no wonder there are so many black anchors mounted on new boats now

  4. I have installed marine electronics for 12 years. Have customer that wants NMEA 2000 off his Crusader 5.7MPI's. Started research today and again there is no simple "plug and play" procedure. A whole new learning process with somethings that is supposed to be simple.

  5. Always Amused by the level of rant..You don't want to pay someone to figure it out for you, you don't like the price of the parts needed..Yet you have an expensive boat...You realize there are people who are trained to do this, yet you would rather try and get that info for free...This is exactly what is wrong with the word today..You want expensive, but you want it for free...So we sell out to the offshore Mcdonalds drive thru mentality while all the local support companies dry up one by one...Good going sir mission accomplished.