New NMEA 2000 network, now analog guages don't work!

[KDNitz]

Just installed a NMEA 2000 network for my 2015 DF40A (only 20 hours on engine). I have the latest version 3.5 interface cable as well as the adapter cable installed (from Browns Point). All engine data displays on my Lowrance Elite 7Ti as expected. However, my analog Suzuki fuel gauge and tach no longer work! During installation of the network the wiring to the analog gauges was not disturbed. Both gauges have backlighting, so they are getting power, just do not work. Please help!

Kurt

[Moonlighter]

Shouldnt be any issues.

Please confirm - you have used the adapter cable to connect the interface to the engine's SDS port? And you did not unplug anything else from the SDS port, or change any other connections under the engine cowl?

If both those are confirmed, the network being created should not have affected the analogue gauges at all. You could test by unplugging the adapter cable from the SDS port and see if the analoge gauges work again(but I doubt very much if they will)

The analogue fuel gauge is not getting signals from the engine in any way - it just gets a signal from the tank sender. So its not even part of the engine wiring harness - which leads me to suspect you may have done something to disturb wiring to the gauges, behind the dash.

Where and to what did you connect the power node for the network? I would look at that connection and nearby wiring connections. The gauges backlights are a separate wire from the engine connections that sends signals.

[KDNitz]

Correct, the adapter cable is plugged into the sds port (see picture in original post). Nothing else under the cowl was touched. I followed your NMEA 2000 document (excellent by the way)! I did troubleshoot by disconnecting the adapter at the sds port and the analog gauges still didn't work... The power node for the network is connected to a spare accessory switch. I had no reason to disturb the wiring to the analog gauges during the network installation ...which is why this is so perplexing. I already double-checked for loose wires but will triple-check.

[Moonlighter]

Ok, check that wiring again and let us know how it goes.

Logic suggests it is most likely a wiring connection issue somewhere behind the dash - you get what Im saying about the fuel gauge pointing to that as the likely source of the problem?

Check all fuses in case during the process of wiring into that accessory switch something touched when it shouldnt have.

Edit- one more thought- just check the main harness where it connects to the engine - nearby the SDS connector, same plug. I just wonder if it might have been loose and been dislodged when you had the side covers off and were routing the adapter cable etc out thru the rigging grommet. Dont think its likely but - Worth checking anyway.

[KDNitz]

Will do. Thank you for the suggestions!

[KDNitz]

Found it!
Grey wire (male/female insulated connection) for tach sender, which is also tied into the same harness as the fuel gauge, was loose. Strange because I didn't go near that wire during NMEA install. Either way glad I found it, also glad the gauges are now working because I am evidently damn near out of gas!!!

Thanks Moonlighter for pushing me to triple-check the wiring again.

Kurt

[Moonlighter]

Good work! I was pretty sure it would be a wiring issue in there.

It should all be good to go now.

Now, when you fill the tank from now on, dont forget to reset the fuel to full in the Elite ti menu. (You have done the boat setup to set tank capacity, correct?)

Cheers!

[KDNitz]

Yes, I have set the boat tank capacity. I have only filled the boat once since installing the Lowrance. My understanding is that it might take a couple fill-ups to get fuel flow, etc calibrated correctly?

[Moonlighter]

You will have to wait and see. Sometimes its perfect right out of the box.

On a 40 I would recommend starting with a full tank, burning at least 20 litres of fuel, then filling up again to full. Compare actual with predicted. Only calibrate if you are more than 1 litre (a quart) difference to start with. You should get it to within a half pint between actual and predicted.

[KDNitz]

Great, thank you!