Updated: I posted a question about this on the excellent Sabre Owners newsgroup and received some great suggestions that I added to the bullet list below.
Since we launched Cadence for the season, we have been plagued by an electrical issue. We’re sailing along, minding our own business and suddenly, everything shorts-out. The chartplotter and VHF flicker on and off, sometimes die. The voltmeter at the panel shows the batteries down below 8 volts.
We switch everything off and the voltmeter reads around 12 volts (not good but enough to start). We crank up the engine and everything returns to normal for a while. Then the problems re-occur even with the engine and alternator running.
The joy of being in a yacht club is that there are lots of people willing to help and no end of opinions. One of the recurring opinions is that electrical issues are simple. It’s all down to breaks and shorts. Not so much in my view.
So far the more helpful opinions have been:
- Load-test your batteries. Done that and they are fine
- It’s a grounding issue. I checked the main ground and it’s fine
- There is an electrical leak somewhere. Agree but can’t find it.
- The newly installed solar panel is the problem. Disconnected and it didn’t fix it
- The recent rewiring of the bilge pump directly to the batteries is the issue. Could be.
- Faulty voltage regulator. Sounds plausible
- Gremlins. Most likely
- Engine gauges are grounded to the keel bolts need cleaning (not sure that this is the case with my boat)
- Loose connection at one of your primary connectors-most a main ground at the engine. Don’t think it’s this as I have checked all this carefully
- Chafed wiring harness. This is sounding likely as multiple systems would be affected by this. The wiring harness that contains most of the grounds which is on top of the engine (almost all yellow wires)
- Other advice: Start by installing a monitoring system
- Get the very best reading you can of the actual battery voltage
- The truest words: “The fix is most likely simple, finding the open connection is the difficult part.”
I read the excellent 12-Volt Bible, cover to cover and tried a number of the suggested tests. Frankly, this only left me more bewildered. I even tried a painstaking leak test which suggested that half the circuits have leaks in them. Oh, goodie!
I have thrown in the towel and taking the boat back to the marina to have the electrician work on it.
Ah, the joys of boat ownership.
Voltage drop can be caused by increased resistance somewhere. Got any warm or hot wires between the batteries and point where you see 8 volts?
Don’t know Jak but that’s good suggestion
Thank you for yet another post in your series “Making Tillerman Super Happy That He Owns a Laser.” I may have to write a post myself one day with links to all of your posts in this series.
Sorry to be so mean. Hope you find the leak soon.
TMan, hope you get a leak!
Kidding. It’s all in good fun
One of the most obvious sources of trouble – but not mentioned in your list – is the connection of the power cables at the battery.
They can look tight and clean on the outside, but still be faulty where it matters. The drill is to remove the cables from the batteries, clean well on all contact surfaces with sandpaper or such, and then make nice and tight again.
Liberal applications of beer can help, but only after you’ve finished screwing around with the cables.
Thanks ODock. I topped up the batteries with beer. That shoudl be OK, right?
After reviewing the updated points, I’m convinced that the beer will ultimately be the most important factor. But I’m surprised that the inhabitant from Dock O doesn’t use beer from bottle, but rather from can.
And I’ve been trying to analyze these Typepad profile images. Are they all from the same Mother image, taken from different distances from the nucleus, with different colors for different commenters? You can tell me to shut up at any time.
Yachties do it in shorts.
Yachties do it with a leak.
Yachties do it with a flicker.
Yachties do it with poor connections.
Yachties do it with lots of other people helping.
The battery connection suggestion is a really good one, except that you’re seeing the problem when the engine is running. If the alternator is turning, depending on the actual wiring, that seems unlikely.
There are two ways I could see this happening. First, something related to a poor connection, whereby the wiring can’t handle the load. E.g. the battery connector issue. I’d look at the main switch and the connections to the panel. That’s the scariest occasion as it may lead to a fire.
The second thought I had was significant load. It’s possible to have a wire ground itself, take on significant load and draw the voltage down. That seemed likely when I saw this post, but the more I contemplate it, I would go with the first item. Unless something isn’t fused (new bilge pump?), a breaker or fuse should prevent that.
If you haven’t already dropped it with your local sparky, I would have someone watch the panel voltage while you jiggle the positive leads, one by one, from the battery to the panel. I would bet a frosty cold beverage that is your dilemma.
As a side note, we’ve greatly enjoyed your blog. My fiancee is a great devotee and keeps me abreast of the latest. Should you find your way across Raritan to AHYC, the aforementioned beverage is on us.
TMan, I am making up Tshirts
Osprey: You are too kind. Will ping you next time I am heading to AH.
Practical applications and advances in such fields created an increasing need for standardized units of measure; it led to the international standardization of the units ohm, volt, ampere, coulomb, and watt.
I am grateful for the standardization of measurements like these. Makes life easier. The metric and english systems are ever at war and I wish we’d just switch over. But at least our electricians don’t have to do conversions to know how much juice is flowing in those wires.
electrical engineer here. I actually investigated a similar problem before.Almost certainly a wiring issue, At the sub or the house
For that kind of repair who would you call? Would you take it to a specialty repair shop or get the help from an electrician in victoria bc? Good things to know. http://www.mikescountrykitchens.com/
This is a great post! I have really been looking into electricians tallahassee fl. Can you tell me where I can find more information about electricians and how they will be able to help me with all of the different electrical things?
I tried to do my own electrical work…worst thing i’ve ever done. I hired an electrician from hamilton and i dont know how he did it, but in a couple hours everything was all good. I dont like to mess with things i cant see that can kill me, so lets leave it up to them. Good post!