NMEA-2000 Network Problem with old I-Command "Classic" Gauges

[john8lyons]

My twin 2008 E-TEC 150-HP engine are connected to older I-Command "Classic gauges. I have been trying to keep these old gauges working. These gauges are so old they use the obsolete Deutsch 6-pole connectors.

The gauges all power on when the ignition key switch is moved to the RUN position. The I-Command gauge configured for the Port engine is working, but recently the I-Command gauge associated with the Starboard engine no longer displays engine data.

Q1: Are there any implications for troubleshooting from the fact that both the starboard tachometer and the Starboard speedometer are not receiving data? My understanding is that they are stand-alone network devices, although the speedometer integrates information from both motors since it provides instantaneous combined fuel usage from both motors.

Q2: I'm puzzled why the network powers on with normal key-on but doesn't power off when the keys are turned off. This is true for the entire network. I haven't been able to discern exactly why this would be the case from the E-TEC literature. My setup is like that depicted in on page 28 of the installation guide.

ASIDE: I am a new user here but have been finding great information here and over at etecownersgroup.com from Jim and others about my old E-TEC engines.

[Phil T]

To eliminate the gauges from the list of culprits, swap out port and starboard tach/speedometer and see if they work.

[jimh]

Q1: Are there any implications for troubleshooting from the fact that both the starboard tachometer and the speedometer are not receiving data? My understanding is that they are stand-alone network devices, although the speedometer integrates information from both motors since it provides instantaneous combined fuel usage from both motors.

Your use of the terms "tachometer" and "speedometer" are interpreted [by your reference to the wiring diagram on page 28 of the installation guide) by mean two separate gauges, one that shows Starboard engine RPM and a separate gauge that shows boat speed data. I hope that interpretation is correct. If so, for that one I-Command gauge to no longer display engine data while a two other I-Command gauges on the same network do display data can be interpreted as follows:

1. There is data from the Port engine being shown on the I-Command gauge configured to show Port engine data, and data about boat speed on the Speedometer I-Command gauge; from this we can deduce that the network backbone must be working, as without that function, the Port gauge and the Port engine could not communicate, nor could the Speed Transducer and the Speedometer gauge communicate.
2. There is no engine data from the Starboard engine being shown on the Starboard I-Command Gauge; from this we can only deduce several possibilities;
   1. the Starboard engine is no longer connected to the network;
   2. the Starboard engine is connected to the network but has stopped sending data;
   3. the Starboard engine is connected to the network and is sending data, but the Starboard I-Command gauge is not connected to the network
   4. the Starboard engine is connected to the network, the Starboard engine is sending data to the network; the I-Command gauge configured for the Starboard engine is connected to the network, but the gauge has a problem;
      1. the gauge configuration has become corrupted and is no longer properly configured to show Starboard engine data, or
      2. the gauge itself has failed in some unknown manner.

Q2: I'm puzzled why the network powers on with normal key-on but doesn't power off when the keys are turned off. This is true for the entire network. I haven't been able to discern exactly why this would be the case from the E-TEC literature. My setup is like that depicted in on page 28 of the installation guide.

The behavior you describe is unusual. I do not have any first-hand experience with these obsolete I-Command gauges. My only guess is that the gauges are getting their power from the network via the direct connection to the boat's battery via the network hubs. The gauges perhaps remain powered on when the ignition key switch is in STOP for some preset duration. I really have no idea exactly what is occurring there. I recommend you visit ETECOWNENERSGROUP and ask user MEAD about this.

[jimh]

Because the two engine gauges are set to work with a particular engine via their configuration using the INSTANCE parameter, the gauges do not directly connect to either engine, but instead connect to the network. Their exact wiring location on the network would not change their configuration. But changing the network connection could detect a wiring problem. The wiring problem could be at any point in the wiring path:

• in the gauge's network connector
• in the pre-made cable connecting the gauge to the network hub; or,
• in the network port connector being used.

[Jefecinco]

It may be possible to reduce the number of possible fault points by switching the port and starboard connections at every junction from the backbone to the gauge, as suggested by Phil.