2007 50 Bavaria Cruiser - All DC is flashing.

[allendick]

2007 50 Bavaria Cruiser
Returning to port one day, my plotter quit, then was able to be restarted. 
That was the first sign.
This did not affect the engine but I discovered it affected all other DC
circuits and repeated several times as I docked and after.
Then the frequency of failures increased to the point where the DC
was completely unusable. 
I assumed a short or heavy load somewhere was causing a main resetting
breaker somewhere to pulse, but do not know where to look if that is the case.
When on, the lights seemed normal brilliance.
Has anyone else experienced this or have insight on where to look?

[JEN-et-ROSS]

Low voltage..??
 the plotter would quit if the DC supply fell below a fairly high specified value... (It happened to me on my brothers boat many years ago)
At the voltage the plotter quits at, and if you've got LED lights they could still appear quite normal..
The engine of course will run all day with no power, starting it again could be problematic though..
As the voltage falls away other services will fail in turn..
Not sure what you mean by a breaker 'pulsing', if there's a fault a breaker will just 'pop', and it's quite normal to reset it once, but if it 'pops' a second time then assume a fault and deal with it later...
I'm only guessing, but I'd start with a multimeter, Check battery voltages (12.6v is perfect), then run the engine (if possible) and check again, it should be a volt or more higher...
If all seems normal on your multimeter then I haven't a clue to the problem,
If not then the problem is somewhere on the Alternator (Regulator)/ Splitter/ Batteries chain or their associated wiring...
Good luck, these electrical problems are always a real headache to troubleshoot...................

[allendick]

Thanks. 

On some electrical systems the main breaker is self-resetting so critical systems do not stay down but attempt to reset. However, if the fault persists, the breaker will cycle. That is so the critical systems work as well as they can but wiring is protected against fire.

I suspect something somewhere is drawing too much, but at first suspected a bad ground seeing as that is a common cause of system-wide issues but logic tends to exclude that.  So far.

Another option is electronic failure seeing as these boats are right in the age range to have the Taiwanese defective capacitors. (Taiwan pirated the formula for electrolytics from the US mfr about then but did not get one critical detail and as a result electronics incorporating these off-brand components started failing a few years back).

I am not at the boat right now but thought I would ask if anyone had experienced this odd failure to cut down my troubleshooting time.

I suspect that I will have to just disconnect things until I find the culprit.

I do have the manuals and have to study them. I went to the Bavaria site and requested them and they came within hours.

https://www.bavariayachts.com/contact/

[IslandAlchemy]

Check your battery connections

[allendick]

Thanks. This happens with shore power and the charger floating, too.

 Always good advice, though, along with checking the ground point, which I have yet to do when I am aboard Wednesday.

The batteries share a common ground on these boats and the single  battery switch actually switches the common ground.

I assume that ground is shared with the charger, too, so would be a common point of potential failure.

[Bavaria 46]

Hi, we have experienced the same issue. In our case the root cause was clear: During wiring work of our new Inverter a short cut happend somewhere. A ground cable was sqeezed during fixing a "nut of a plus cable shoe" at the new Inverter main switch and melted down. After fixing the primary damage the whole DC System was always switching on for 1s and off for 3s. This repeats all time. The only thing that solved the problem was exchanging the whole DC Main panel 301. Quite expensive, but in our case a topic for our contractor, who installs the inverter. It happend in the period where Bavaria was in financial trouble. It took 6 weeks to get the spare part.
BR Ingo

[allendick]

Thanks.  I hope it is not that, but that is a hint.

[allendick]

I discovered that the panel 301 is good.  I jumped from the batteries to the panel and everything works fine as long as the jumper is on.

The main bus cable has power where it connects to the battery and fuse and descends into the bilge to cross to the nav station, but is dead when it connects to the house battery switch.  I cannot see the exact routing or if there is a connection or breaker of some sort in between.  I am thinking I may have to disassemble the nav station to gain access and see where it emerges and goes from there before reaching the battery switch.

Any thoughts?