No Power

[Double Trouble]

Hay Seabob hope all is well. I have another puzzle on my 275 explorer Went down to check her out my DC power breaker is on my stereo works fine if I turn on any one of the other DC breakers ie water or head or cabin lights nothing goes on but my stereo goes off . When I turn the breaker off the stereo goes back on. Did not have time to investagate yet any ideas. also everything up on the console works.

[GoneFission]

Sounds like a short...   :(  

Does the stereo go off if ANY breaker is closed?

[seabob4]

DT, Cap'n John,
First and foremost, a direct short would indicate a tripped breaker.  DT hasn't given us that indication.  So, barring that condition, some analysis is necessary.

Now, stereo memory is direct to the battery (through the batt switch), stereo power usually comes from the helm, or cabin feed.  Switched.  Now, the question posed is this.  Turn anything on, DC-wise, and the stereo cuts off, but yet no breakers are tripped.  Turn all the other breakers off, and the stereo operates.  Now, in my experience, electronics really do not consume that much power.  However, should the power available through the DC system be on the minimal side, such that an additional load be placed on that system whereas nothing is seeing the voltage it needs to operate, would that not point to a battery?  The key, at least to me, is the additional loads.

So my suggestion is to put a meter on the house battery and see just what condition it (they) are in.  Try the same functions with the charger turned on.  Let us know the outcome.

[Double Trouble]

OK Seabob will check that out ,but battery charger is on and is showing green lights for both batteries.I will put a tester on the batteries over the weekend thanks.

[bdtsr]

Good evening. I'm new to this forum but have had my own marine electronics/electrical business as well as owning boats for 30+ years. To check your batteries, disconnect them completely, charge them for 24 hours with a known good automatic charger, test with a 100 amp load tester for 10 seconds, check voltage while testing as it should not drop below about 11 volts. If the batteries test good, check ALL connections for corrosion. What you are describing is a current limiting condition. When items are turned on and draw more current than can flow, things shut down due to the voltage drop.

Good luck, Brian

[seabob4]

Brian,
Very good advice.  Boats live in a s h ! t t y environment, and it can only take a few years for corrosion to wreak it's havoc.

If RickK didn't already say it, welcome to this forum!  Great boats owned by some great people!  Happy New Year!

[bdtsr]

I have seen this WAY too many times, from battery terminals to fuse holders and so on. Unfortunately corrosion WILL work it's way up the multi-stranded marine wire if not sealed off.

[seabob4]

Brian,
Even if sealed with adhesive lined shrink sleeving, the "black" will show up.  And if it's in 1 harness, most likely it will be in all.

[bdtsr]

For battery cables and critical items I always solder the connector on then use liquid lectrical tape and heat shrink tubing. Works very well. But you are very correct it will eventually work up the wire. Braided antenna wire is really bad for this since the insulation is exposed to the elements and will crack letting water in.

[Double Trouble]

Welcome to the forum and thanks for the advise will try it as soon as i get down to the boat. I was planning to go today but its a little cold here in NY.

[Double Trouble]

OK got down to the boat today for a little while,checked voltage at batteries 13.5 volts same with charger off pulled panel in cabin checked voltage at main DC breaker 13+volts.I am thinking of checking accessory by removing lead from its breaker and touching it to main to see if anything goes on.What do you think Ihave a 2000 275 explorer maybe you remember panel setup if you can think of anything else let me know.

                                            Thanks        
                                            DT  

[seabob4]

DT,
Just for s h ! t s and giggles, check the voltage on the output side of your main, and also check resistance with the breaker in the on position.  If all checks well, then turn on your stereo and then turn on another DC appliance and check the input and output sides of both breakers for voltage.  It would appear to me that your issues are panel related.

[bdtsr]

Does the engine(s) start ok on each battery(should only take one battery to start, use selector switch)? A battery may check fine while not under a load (surface voltage) but will fail when a load is applied. This is where a battery load tester is handy. Harbor Freight has them pretty cheap. Remove and clean all connections. Turn on one circuit at a time and see if you can duplicate the problem with another circuit.

[seabob4]

DT and bdtsr,
That is also good advice, as far as a batt showing "good" voltage at rest, but once a load is applied...?

bdtsr, a question.  Since any DC load placed on the batt is basically minimal, in other words, not like a macerator pump drawing 15-17A pumping out a fishbox, wouldn't one think that a "suspect" batt could sustain a minimal load, whatever that load may be?  Bilge pump?  DC cabin lights?  DC side of the reefer?  All minimal amp draws.  

Just curious, and I, along with DT, I'm sure, would appreciate the input on that thought.

[bdtsr]

Guys,
I have seen both where say a 5 amp load is ok and where it takes much more to pull the battery down. An older weaker battery would do the latter but a newer battery with a bad cell would fall off right away. Interesting thing is, batteries will fail in a second at times. Crank up in the morning, run and crank all day, then wham, lights come on but better breaker out the starter rope!