can bus votage low alarm

[fishslapper]

new 300 Suzukis everything fine but twice I have got an alarm for can bus voltage low less than 9v...battery voltages are fine...nothing seems wrong...any ideas?

[Moonlighter]

I would check the NMEA2000 network power source, make sure connections and wires are good, and especially check the fuse that should be in the +ve network power wire. Make sure fuse contacts are good. By check, I mean undo connections if possible, clean and reinstall.

If that checks out, then check that you are getting good 12v at the network power connection point, measure with a voltmeter.

Let us know how that goes.

Any further info such as under what conditions/circumstances this is happening? When starting engines? Or operating anchor winches??

My point being that both the network and your new Suzukis require a really good power supply. If the engines ecu's dont get good power some really weird things can happen. Same with the network. So battery condition, wiring condition and earths are very important.

[white diamond]

I got the same alarm this weekend on my DF300. The Suzuki gauge was showing 12.4 volts when I turned the key on, then got the alarm when I pressed the start button. I just have one motor, no network. The only thing on was a VHF radio. Why would I get <9 volt alarm when the gauge read 12.4 volts before starting?

[artdf175]

a number of issues can come up
the ECU needs a strong power source

old battery - close to end of usefulness
Batt voltage reads ok but is starting to lack the required CC Amps
you turn on the key to start position and the engine drawdown causes voltage to drop below 9V as it takes all the power to the starter..
2). check those battery terminals.. take them apart and brighten them up with a file or sandpaper. any corrosion will create a problem
3). could have a bad connection to the "white power" power sorce that runs
through the ignition that feeds the ECU.
there have been some reports where the white wire power source comes off the power terminal on the starter. Bad idea!
art

[Moonlighter]

I got the same alarm this weekend on my DF300. The Suzuki gauge was showing 12.4 volts when I turned the key on, then got the alarm when I pressed the start button. I just have one motor, no network. The only thing on was a VHF radio. Why would I get <9 volt alarm when the gauge read 12.4 volts before starting?

I agree with Art - you have a voltage drop issue, either battery is low (may be on its way out - have it load tested is a good idea) or a wiring issue anywhere between battery and your busbars/switch panel. Could be a bad connection or internal corrosion in wires.

So the short answer is that you need to find the weak link and fix it.

12.4 volts on a resting battery is about 80% charged, according to charts I have seen.