Wiring

[john6206]

Hello all. I’m wondering if anyone could steer me toward a good book on basic boat wiring.
there seem to be quite a few of them. I’m thinking about Don Casey, “Sailboat Electrical Systems.”
the blurb doesn’t say, “for dummies,” but it seems to be implied.

I’m fairly handy in most areas, but boat wiring seems to be a real weak spot. For example, I installed a new stereo, and now the VHF doesn’t work. It kind of looks like a plate of spaghetti hanging on the wall down there, and it’s a little intimidating. House wiring is easy to figure out by comparison (And don’t get me started on the dang trailer lights!).

fortunately it’s a tiny boat without much to wire. it seems the easiest way to start might be to take it all out and start from scratch, but that kind of intimidates me more!

I’m sure if I looked into hiring it out the cost would drive me back to DIY.

 

[dlochner]

Charlie Wing's. Boatowners Illustrated Electrical Handbook. (Amazon Link). Clear, concise, easy to follow.

 

[Ken Cross]

Make sure you buy good materials and go slow. It's not a difficult job.

As for your trailer lights, it's almost always a ground problem. any chassis ground is always suspect including connections between structure. Run a separate ground wire to each light and you will likely never have another issue with it. And yes, use marine wire here too.

Ken

 

[Johnb]

One of the clearest I have ever read.

 

[Don S/V ILLusion]

I installed a new stereo, and now the VHF doesn’t work.

The two should be mutually exclusive - they both have different power leads, coax and antennas. All you need to do is figure out what you did which effected the other one.
A couple of hints -
Do both have power? That eliminated the 12V problem
Do both still receive? That eliminated the coax/antenna problem

 

[Project_Mayhem]

Sometimes its easier to start over and sometimes its easier just to tap off of an existing line (granted the wiring is adequate). Can you snap a picture of the wiring?

Neutral and ground are usually tied together in a breaker box. This way if a wire touches a box or conduit, it'll short for a second and then trip the breaker. Ground and neutral are usually tied together in AC wiring just as ground and negative often are in DC circuits. So AC and DC wiring is actually more similar than you think. Only two wires are typically required for a device to work

 

[Crazy Dave Condon]

What is the model and manufacturer? Ate the wires color coded? Do you have AC as well as DC?

 

[dlochner]

Sometimes its easier to start over and sometimes its easier just to tap off of an existing line (granted the wiring is adequate). Can you snap a picture of the wiring?

Neutral and ground are usually tied together in a breaker box. This way if a wire touches a box or conduit, it'll short for a second and then trip the breaker. Ground and neutral are usually tied together in AC wiring just as ground and negative often are in DC circuits. So AC and DC wiring is actually more similar than you think. Only two wires are typically required for a device to work

On a boat this should never occur. The ground and neutral should be completely isolated. The AC ground (green wire) should be isolated with a Galvanic Isolator or isolation transformer from the shore ground. There are all kinds of bad things that can happen if the neutral and ground are connected on the boat. This is sharply different from house wiring.

Before messing with AC, be sure to get a good book like Charlie Wing's, read it and understand it or hire an ABYC electrician. Boat AC and Shore AC are very different critters.

 

[Kings Gambit]

Whenever I have to access the wring behind the panel to do something, like to install a new stereo which I did last year, I have to check closely that I did not loosen a connection to something else, which then does not work (after I put it all back together!). The most insidious trouble makers are the crimped connectors at the ends of wires. They become loose over the years so the wire does not keep a good connection if pulled slightly, or jiggled too much. To find the bad one you must tug slightly on the wires of the suspects. If it comes out recrimp with a new connector. Problem solved. But more to your point, specifically. The antenna to my VHF has little play. If the panel (holding the VHF) is pulled out too much, the antenna wire backs out some. So, if the VHF lights up but doesn’t sound off, that’s likely your problem.

 

[Terry Cox]

Hi John, as a footnote DC boat wiring, or marine grade wire, needs to be of the proper guage for the appliance used and always use stranded tinned copper wire. Whatever book/source you use should tell you the amp draw of the appliance and the wire size that will safely support that draw, whether a charger, radio, light, autopilot, shaver, etc.

 

[john6206]

Hi Everyone - Thank you for your insight!
I purchased the Casey book. It promised to give advice without baffling me too much with theory and equations. I'm reasonably intelligent, but I do get befuddled sometimes by technical stuff.

To answer a few questions -
It's a Capri 18. It has cabin lights, nav lights, a VHF and a Stereo, very simple, one battery. It does have a breaker panel.

Previous owner installed a knot meter and a depth gauge, but when I purchased it, the transducer was broken. The depth gauge blinks zero, and the knot meter made a terrible high pitched whine - the knot meter is now in a plastic box in my garage and the depth gauge just sits there blinking at me.

Goals:
*I need to replace some of the nav lights - I'm assuming the wiring on those is fine and it's the fixtures that are broken. The bow light it's pretty obvious it's the fixture (collision maybe?). Replacing the fixtures does not represent a challenge.

*I'd really like both the VHF and the stereo to work. They do share a lot of wires, as in one wire comes out of the spaghetti and splits in two. They have different antenna - both mounted on the transom.

*I'd like to put the VHF antenna on the mast. I'm also thinking about putting a windex up there . . . have to check on the geometry. Not sure it's necessary to have the antenna on the mast - it's not like I'm going 50 miles offshore, but before I broke the VHF, the handheld had much better range. If it wouldn't complicate mast raising, I don't see a reason not to.

*Replacing the transducer on the depth gauge might make sense. A depth gauge could be helpful, I hear it's not so much fun to push a wing keel out of the mud, haven't experienced it yet. Might replace The whole depth gauge, might just remove it. Right now it's the worst of both worlds.

*Most ambitious project would be installing a 12 volt outlet in the cabin so we can charge phones. This might involve cutting into the fiberglass and digging holes in the foam to run wire. I could probably mount the outlet to the wooden trim instead. I don't want one that hangs there and looks like I didn't know how to install it.

*I bought an outboard that has a little alternator. It wouldn't hurt to install the wiring for that while I'm in there - but the wisdom I've heard (mostly on this forum) is that it's not going to do much to top off the battery. It's a bit over sized for my boat and I've never had it beyond half throttle - and obviously on a sailboat the goal is to turn the motor off.

 

[b.needalman]

1. Invest in a descent ratcheting crimper. You CANNOT make a crimp that will stand up to the marine environment with $5 automotive crimpers, no matter how strong you think you are. A quality wire stripper makes the job go faster but you can get away with the striiper on the automotive crimper.

2. Buy a tube of dielectric (bulb grease) at the auto store. This stuff is magic. Put it in the connectors before making the crimp. Also inject into switches, cover bus bars, screw connectors, etc. Corrosion is the enemy and dielectric grease is your best defense.

3. Buy adhesive lined heat shrink in length plus a heat gun or hair dryer. An open flame will work but requires care. Heat shrink tubing is much cheaper than buying heat shrink crimp fittings. Another defense against corrosion.

4. Buy only reputable brand (e.g. Ancor) crimp fittings.

 

[ggrizzard]

No fiberglass cutting required.
You can buy a 110/12v USB receptacle combo
for an existing outlet at a big box store or local elec. supply house.

 

[b.needalman]

The stock USB outlets, either 12v or part of a 110 outlet will not charge the latest phones as quickly as possible. They keep coming up with improved charging regimes that require special USBs. Best to use a 12v outlet that takes a plug usb adapter made for your device.

 

[ggrizzard]

I still use a Blackberry...
So what do I know???

 

[john6206]

i don’t have any kind of outlet now. That’s why I was thinking about mounting something to the front of the cabin seat, the wiring would be in the storage area under The seat and it would be close to the battery (but not to the breaker panel . . . Might have to reconsider).

i had considered usb, good call.