Mercury Smartcraft - Communications Error

[P999mm]

Have a Smartcraft - Verado 350 "Communications Error" hope someone can point me in the right direction to fix the issue.

Normally, when I turn the ignition switches on this happens
- Alarm for about 5secs, all lights on the binnacle turn on, then only the ones relating to the engine that was switched on remain lit. Neutral, sync and the Transfer Light usually stay on. When I switch on the other engine same thing happens and the neutral light for that engine remains lit. Smartcraft gauges come on. Tilt works for both engines and both engines start.

Now, starboard engine is normal as per above, but when I turn on the Port Engine, no alarm, but the lights on the binnacle come on and then all turn off. Smart craft gauge for the port engine turns on and then in about 1 min it reads critical communications error, return to port. The trim on the binnacle does not work and the engine does not turn over. The trim on the side of engine does work.

So far, have unplugged and re-plugged connections to the control boxes under the dash, made sure all of the wires to ignition switches are secure and also the gauge wires.

Did speak to a Mercury rep at the Boat Show, he suggested that I check all the connections.

Any thoughts on what and where the issue could be would be most appreciated. Where should I be looking for a loose connection. Is their a particular circuit that I should be tracing.

Thank you in advance for any guidance or tips anyone can provide.

Happy Super Bowl

 

[zurk]

replace port battery.

 

[P999mm]

Morning Zurk, thank you for your reply.

Yes, when the problem first surfaced, I replaced both Port and Starboard starting batteries. No change after the new port battery was installed.

- Will take another look at the port battery wiring and the connections/fuses at the port engine.

I see lots of threads on this issue on the web/hull truth, but most of the threads end before the actual "fix" is posted or the fix is unrelated to my issue. I guess it is a process of elimination, so will keep working on it.

Thanks again for the reply

 

[zurk]

swap port and starboard batteries. either that or its the ECU or bad wire. hopefully its just the battery. ECU is expensive and cables are a pain to find a bad ground.

 

[P999mm]

Thanks Zurk

Will swap the batteries, good idea. Hopefully get it down later this week.

 

[P999mm]

Hello Zurk, was out of town the past few weeks, so didn't get to this until this past weekend. Swapped the batteries and got power at the port binnacle and everything is working. Will replace the battery that is not performing. Thank you for your suggestion to start with the easy stuff. Thank you.