How many wires are too many?

[jaschrumpf]

Looking over the wiring in my Newport 28 with an A4 engine, it seems to me the wiring is a bit haphazard. From what I've seen so far, the main positive lead from the battery goes to the starter, and then a wire goes from there to the coil. After that, there are masses of red wires that are connected here and there together onto one wire that goes to either the positive terminal on the starter or to the coil. Shouldn't there be a bus or something that all the positive leads are connected to, rather than joining them and running the common wire to one of those two terminals?

Of course, there is the bus at the DC panel, but where that hot lead comes from is still a mystery at this point.

And it looks like every red wire is also connected to my ammeter, which does nothing when the engine is running, regardless of the load. I thought that that ammeter connection went across the main black lead to sense the current.

And finally, aren't green wires the alternative for black? Or is it green/red, yellow/black? I really want to make heads and tails out of this wiry rat's nest, and it's hard to figure out what's going where with all these joins and color changes.

Thanks for any info!

[sailingdog]

IIRC, current ABYC electrical code has replaced the traditional black wire for ground with yellow, since it will help prevent confusion between the black DC ground wire and the black AC hot wire. The DC positive feed is still red.

[rewell6]

Is this new/original work, if so leave it the way it is.

If it is something jury rigged by a previous owner then you might want to fix it. However this is not for the faint at heart. You will have to know AC and DC to fix or replace the wires.

The ammeter should be across the current of the DC load. Which should be the red wires, not the black.

If you have no idea what you are doing ask for help or leave it. You can easily create such a mess that it would cost a fortune to fix.

My brother wired houses for a while and he could not understand DC. He would work on my dad's boat when I was away and I would have to spend an hour just trying to understand the mess he made.

[sailingdog]

I would agree that if the wiring is a problem, it is probably easier to rip it all out and start over again, since fixing someone's bastardized job will often take longer and cost more than doing it from scratch to begin with.

[SEMIJim]

Just echoing what some of the others have said. If you don't really understand electical systems, probably best to leave it to somebody who does. Seeing the mess some homeowners make of plain old residential house wiring, I can just imagine what they could do to a boat's electrical system. Oh, wait, I don't have to imagine it: I've seen it on a couple of the boats we looked at

Jim

[SEMIJim]

Originally Posted by rewell6

The ammeter should be across the current of the DC load. Which should be the red wires, not the black.

ITYM "in line with." "Across" would result in pyrotechnics

Jim

[yotphix]

Most often when I come across an old boat where the electrical work was done by someone "handy", I save time energy and money by stripping out everything and starting fresh. Before removing anything I make a drawing of what is going to be needed and carefully chose wire sizes. Then I go over the plan carefully to see if it can be simplified in any useful and practical way. Then I actually plan where the wires will physically run in the boat, and how I can make the runs as neat and secure as possible.
Then it's time to go shopping. Once you have a clear plan and everything you need to execute it, you get to the fun part. Remove everything! You will take out a large garbage bag full of wire in most boats. And you will likely find lots of evidence of poor planning, execution and failing connections that more than justify what you are doing.
While you are doing the install, label label label and label some more. Make it so the next guy who comes along would have to be an idiot not to understand which wire he is looking at no matter where it is.
If you don't have the skills and the tools to do this yourself, pay someone, but make sure that they do a thorough job. No point if they just fix a couple of problems and throw in a few cable ties and call it done. You want it to be better.

[rewell6]

Originally Posted by SEMIJim

ITYM "in line with." "Across" would result in pyrotechnics

Jim

That's right Jim, my bad. I just wasn't clear enough.

If you don't understand the wiring get some help from someone who does.

Is the boat old or new?

[sailaway21]

It is difficult to know from your post if we're talking about the usual maze boat wiring can resemble or authentic spaghetti.
Yotphix post about says it all, although I don't believe he emphasized labelling as much as I'd like.(g) It cannot be emphasized enough that, if you do not know what you are looking at, it would be far wiser to hire a pro to do the job. It will save you money in the long run, in the way that you save money by bringing your car to the mechanic when it is acting up, and not after you have disassembled the entire engine.(g)

If you do know your way around dc juice and boats, I would advise taking plenty of time on the planning stage. It's one thing to say you're going to run these wire in conduit to over there, it may be quite another thing when you try to figure out how you'll secure the conduit. If it looks obvious and straightforward, you've probably overlooked something. Did anybody mention labelling?

[essman]

Normally, in most installations, there is a red lead that goes from straight from the battery to the starter. Then there should be another red lead that goes from the battery bank through a some type of master DC breaker to feed the various circuit breakers / switches for everything else.
Doesn't sound like this is what you have on you boat, which is very common. Over the years things get kind of hooked up haphazardly. Makes it very interesting when you work on boats and are trying to figure out why electrical things aren't working.
Ammeters should be hooked to some type of shunt, which should be hooked to the black or negative lead coming off the house battery. Current flows from negative to positive. The shunt should be hooked in the circuit right at the battery, before anything else comes off of it.