Wiring Mystery

[Heron]

I've been working on my vessel all winter in a heated building. Much of the work was redesigning the interior. I was using both AC and DC for lighting. The "house lights" were working fine for the whole project. Just last week, I turned on the battery switch and, no cabin lights? My service panel appears to be in tip top condition, wiring looks upgraded along the way and I haven't modified any of the wiring during my project.

At the same time, the meter which indicates if the batteries are charged for both banks stopped working. I also have a LINK system which indicates that my batteries are fully charged and operational. The circuit just below my house lights are also not working but EVERYTHING else is.

The mystery is that one day I turned the lights off, turned off the battery switch and they never came back on again. Any ideas for cause? Where do you start to figure out the source of the problem. I fully admit that wiring and electricity are not within my skills.

HERON

[Duesouthpacific]

get at electricity tester and go up and down you wire finding out up to which point you have juice to. You also could have a minor surge thats coursing thrue one main channel

[DeepFrz]

If I were you I would start by buying and reading the book "The 12 Volt Doctor's Practical Handbook".

[hellosailor]

Second the motion to buy the 12V Doctor book. And then to start with a multimeter or test lamp and confirm where the power stops flowing, step by step. Odds are something failed or blew or a squirrel ate a wire--these things do happen.

If there were any electrical storms--a nearby strike CAN blow fuses from inductive surges, even if there is no other damage or sign of it.

[senormechanico]

"The circuit just below my house lights are also not working but EVERYTHING else is."

IMHO it sounds like you're very close to the problem. Look at the panel bus bar where these switches/circuit breakers are located.

Steve B.

[Lynx]

Sounds like something is loose, broken or an unknown fuse blown before the house light circuit.

In addition to the 12v book I recommend one of the home elctrical science kits. Have somebody go behind you and break something and fix it.

[NoTies]

Often a DC panel will be split with the interior lighting & services running off the house bank and nav lights etc running off the engine bank. The first thing I would check is the house bank isolating switch. Check voltage on panel side of the switch with the lights off, if there is 12V there then turn the lights on and see if the voltage drops significantly. If it does then the switch or connections between the switch & battery are likely to be the cause. Of course if there is no voltage on the battery side of the switch then the problem is between there & the battery.

[Alan Wheeler]

Just to clarify Pete. You have a switch that allows you to use both AC and DC for the same lights?? If yes, then you will have a mains transformer somewhere that is creating 12V for the lights. It most likely will be just 12V AC. It doesn't need to be DC. Most likely a fuse will be protecting the Primary 230V winding of that trany. Look for a failed fuse. If you have glass fuses, it is common for them to get a little corroded, just enough to lose contact and not conduct. So wiggle all fuse caps.
Hope that helps.

[Sandero]

Speaking of electricity, perhaps someone might have a good wiring suggestion which addresses a "problem" I "created" when I did a rewire a few years ago.

My system uses a small Optima AGM and 2 - AGM 8Ds for the house bank. The Optima is charge by an Echo charge.. whether when running the engine or on shore power charge (rare). What I found is that the original wiring "harness" for the engine wiring also includes the engine instruments and engine lighting as well as a bilge blower when the engine is running or even the key switch left in "position 1".

Effectively the Start battery not only starts the engine, but once running operates the blower and the instruments. This results in a constant drain on the Start battery and the Echo charge seems not to be able to keep up. I suspect it is mostly the blower sucking up all the amps.

I suppose one solution would be to remove the echo charger and install a device which distributes and (isolates) the alternator output to both batteries so I could get more amps into the Start than the Echo charge pute out. Would such a device sense the drain on the Optima and keep it topped up? It makes no sense to move all the loads noted above to the house bank.

What say you?

Jef
sv Shiva

[Heron]

Thanks for the responses. I will purchase the book recommended. One of the responses suggested that an electrical surge may have caused the problem. It never occurred to me that a boat stored indoors would have exposure to lightning. However, I did have the batteries active and the charger going when a thunder storm did pass. It was only a couple strikes of lightning but maybe enough to cause the surge through the DC panel into the AC lights?

Somehow, my brain is not "wired" to understand electricity very well. If I'm going to cruise with this vessel, I best spend more time learning about the mystery of electricity!

HERON

[Alan Wheeler]

To understand electrical systems, just think of it all as a water system. The batteries are the water tanks. The charger are the pumps to pump watr to the tank from the "wells". The wiring is the water lines from the tank to the sprinklers which are the end users of the water. You have water pressure which is voltage and water flow which is current. So just think of, how do I get the rquired flow and pressure to my sprinkler at the end of the line. How do I get the correct volume of water to the tank. How do I keep the tank at a correct level so it does'tn run dry or overflow. Simple really.....as long as you understand plumbing that is :-) if you don't understand plumbing, then that's easy as well. Just think of plumbing as an electrical installation.....;-):-)

[Heron]

Hi Dave,

Great explanation of how electricity is like water. I took a careful look at the rear of the panel. It looked like there was some corrosion to the ground bar where the black wires were connected. I removed the wires, used a small wire brush to clean the contacts and put the wires back in. All lights came back on.

Is there anything you can do to minimize the corrosion? Any solvents or grease?

HERON

[mangomuffins]

If you check with a local electricians supply, you will probably be able to find a spray (forgot the name of course) that elecs. use to protect connections from corrosion. good luck!!

MM

[DeepFrz]

Corrosion Block
Lear Chem Research
A superior anti-corrosion, lubricating and penetrating compound designed for the marine industry. Recommended for use on electrical and electronic equipment.

Strike-Hold
A spray on moisture barrier for completed wiring connectors. Replaces moisture and forms a dry shield with a dielectric strength of 38,000 Volts

[Alan Wheeler]

There is nothing that desolves the corrosion (well nothing that won't also desolve the wires as well that is). As listed above, there are several products that do a good job at protecting. CRC Softseal is another to add to the list and Amsoil also do one. I have used both and see no real difference. In fact, they both smell the same.