grounding wires

I have pulled all the wiring out of my boat and im starting fresh. I started with the lights and have a ground from the bow to battery in the back of the boat. Can I splice multiple circuits in to that ground, or is that asking for a fire?

Re: grounding wires

Use a large enough wire guage for the loads you intend, and use a terminal strip. Done right and you won't have a problem, though it will make troubleshooting easier if you do.

Re: grounding wires

Bring all the grounds back to a ground bus, like the one shown in this photo (to the right of the fuse block). You'll bring a large enough wire forward to the ground bus to handle the combined current.

Re: grounding wires

davidhicks said:

I have pulled all the wiring out of my boat and im starting fresh. I started with the lights and have a ground from the bow to battery in the back of the boat. Can I splice multiple circuits in to that ground, or is that asking for a fire?

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No.

Don't start with the lights, start with a plan.

Remove that wire and do what the others have told you. Run a heavy gauge (black or yellow) wire from the battery negative to a negative buss near the helm. The wire must be able to handle the current from every electrical device except the engine starter. Now, connect the negative wires from each device to that negative buss.

Run a red wire, the same gauge as the negative wire from the battery to a fuse block mounted near the griound buss. This wire must have a fuse within seven inches of the battery terminal to protect this wire.

Connect your electrical loads to the fuse block, using appropriate sized fuses for each circuit.

The above three paragraphs will not make you a marine electrician. I strongly suggest that you get one or two books on boat wiring and study them and follow their diagrams.

Re: grounding wires

And my only comment to the photograph is don't use the same color wire for everything.

Use black or yellow for ground like the previous poster said.

Re: grounding wires

RE the photo: That is beautiful wire management. Nicely done!

Bruce's comment is on the money, even if the terminals are color coded (which they seem to be, but detail is hard to see).

Another issue with color-coded terminals is, they are color-coded for size, not application. IOW, red terminals are generally for small wires, blue for mid-sized, and yellow for large gauge wires.

Re: grounding wires

Here is a link to the suggested color coding and current capacity for boat wiring:

http://www.cncphotoalbum.com/doityourself/wiring/wiring.htm

Color coding the wires allows you (or your paid by the hour mechanic) to trace the wires without cutting the straps and tugging on them. This is important when troubleshooting.

Re: grounding wires

I did the same thing as the wiring at the back end of the boat was a nightmare. I ended up installing an inexpensive 6 fuse/circuit breaker from Bass Pro ($38). It was worth cutting the access hole in the dash. Instructions said a -ve bus bar is optional, but I ended up getting a 5 point bar and put it under the dash as a -ve bus bar.

It made the job complete and only one red and one black (would use yellow for this) going back to the battery. I put the bilge pump on separate wiring to the breaker panel. The circuit break has six pig tails that give you the same thing as a +ve bus bar.

Re: grounding wires

David - I'm glad you're going for the rewire job yourself. Take your time, use ty-wraps (zip-ties) and a sufficient number of tie down points. Surf the internet and you'll find some good articles on marine wiring. You will also probably run across some good reference materials on terminal sizes and applications.

As one person mentioned, the color of a crimp terminal corresponds to the wire guage it can accommodate. The size of the lug that it fits onto is something else entirely. Therefore, the same wire size (i.e., insulator color) is usually available to fit 2 or more different sizes of of lug (screw). This chart illustrates the different sizes available.

http://wireconnector.info/insulated-ring-terminal.htm

One more note concerning wiring - silicon grease. I operate in salt water almost exclusively and corrosion is major consideration. I put a small amount of silicon grease on every metal wiring component in my boat's electrical system. Every ring terminal, every fuse, every screw terminal, everything. (Almost 10 years without a failure.) Put a small amount of grease on permanent connections before you make the connection. Putting it on afterward will prevent surface corrosion, but will not necessarily prevent corrosion that can occur in between the contact surfaces. (The silicon grease will not inhibit current flow through a connection.) I even put a small amount inside of the terminal before I insert the wire and crimp it. Again, you might want to search in the Electronics Section of this forum on this subject a bit.

Re: grounding wires

I did my entire boat like that, I ran a really heavy POs and NEG wire from the front to the back and just tapped into it where ever I needed to to, saves a ton of wire.

I got the idea from an obsolete wiring harness I got from work, they did it the same way.

On mine as soon as I connected a wire I out a small flag on it with masking tape and wrote what it was and where it went i.e. BILGE PUMP +, it makes it easy to keep everything straight.

Re: grounding wires

Woodnaut said:

One more note concerning wiring - silicon grease. I operate in salt water almost exclusively and corrosion is major consideration. I put a small amount of silicon grease on every metal wiring component in my boat's electrical system. Every ring terminal, every fuse, every screw terminal, everything. (Almost 10 years without a failure.) Put a small amount of grease on permanent connections before you make the connection. Putting it on afterward will prevent surface corrosion, but will not necessarily prevent corrosion that can occur in between the contact surfaces. (The silicon grease will not inhibit current flow through a connection.) I even put a small amount inside of the terminal before I insert the wire and crimp it. Again, you might want to search in the Electronics Section of this forum on this subject a bit.

Click to expand...

+1 on the dielectric grease. I may be imagining things, but it also seems to makes it easier should you ever have to take it apart. If you wind up getting overwhelmed, there is a website that will build you a custom wiring harness. Search ezacdc. They also have a good wiring forum for questions. Good luck!

Re: grounding wires

5150abf said:

I did my entire boat like that, I ran a really heavy POs and NEG wire from the front to the back and just tapped into it where ever I needed to to, saves a ton of wire.

Click to expand...

I am assuming you have a bus at the end of those wires and also used a circuit breaker at the battery end on the POS wire.

Re: grounding wires

The latest job, a 1974 Aquasport 19-6...


The 30A fuse just to the lower left of the batt switch feeds the positive bus, which feeds the helms ans accesories, 10GA. This is "switched" power, turn the batt switch off, it kills the helm and everything else, except stereo mem. and bilge float switch, which are wired to the house batt term. on the back of the switch.

Note how there is only one extra termination on the house batt, the ground that feeds the ground bus...

Re: grounding wires

And if any of you may be wondering why there is a red cable on the batt neg ground post, well, my customer got his cable fro genuinedealz.com, and they have a "value" priced 2GA that is $.60 cheaper a foot, so he figured with black shrink sleeving, all would be able to tell the difference...hey, he's my customer, I do what he wants. Hopefully no "on-board welding" in the future...

Re: grounding wires

seabob4 said:

And if any of you may be wondering why there is a red cable on the batt neg ground post, well, my customer got his cable fro genuinedealz.com, and they have a "value" priced 2GA that is $.60 cheaper a foot, so he figured with black shrink sleeving, all would be able to tell the difference...hey, he's my customer, I do what he wants. Hopefully no "on-board welding" in the future...

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Yikes...seems like an accident waiting to happen to me! How many feet was the cable?

Re: grounding wires

seabob4 said:

The latest job, a 1974 Aquasport 19-6...

The 30A fuse just to the lower left of the batt switch feeds the positive bus, which feeds the helms ans accesories, 10GA. This is "switched" power, turn the batt switch off, it kills the helm and everything else, except stereo mem. and bilge float switch, which are wired to the house batt term. on the back of the switch.

Click to expand...

Not a good idea to "daisy chain" the terminal block with wires (as on the + side of the strip). ALL the current from the ALL the posts have to go through the first "loop". It's much better to use terminal shorting strips.

and GET RID OF THAT +RED / -RED BATTERY CABLE.

Re: grounding wires

seabob4 said:

And if any of you may be wondering why there is a red cable on the batt neg ground post, well, my customer got his cable fro genuinedealz.com, and they have a "value" priced 2GA that is $.60 cheaper a foot, so he figured with black shrink sleeving, all would be able to tell the difference...hey, he's my customer, I do what he wants. Hopefully no "on-board welding" in the future...

Click to expand...

Well, use the red cable but put put a couple wraps of black (or yellow) tape around the cable at each end to "color code" it.

Re: grounding wires

5150abf said:

I did my entire boat like that, I ran a really heavy POs and NEG wire from the front to the back and just tapped into it where ever I needed to to, saves a ton of wire.

Click to expand...

You didn't splice other wires along the length of the wires, did you?

Re: grounding wires

If you get a fuse block like this...


fuse block

it will make wiring your boat much easier.

Heavy gauge + and - wires from the battery to the fuse block (with breaker at battery) and all accessory + and - wires running back to the fuse block. I installed that one on my boat and really like it, high quality.

Re: grounding wires

RickJ6956 said:

RE the photo: That is beautiful wire management. Nicely done!

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Thanks. I'm a EE and used to design industrial control panels in a previous life.

As someone here said - start with a plan. I did a complete wiring diagram and wire list before ever touching a single wire. After that it's a piece of cake - one wire at a time and mark each wire on the diagram with a hi-lighter as you install it.

And my only comment to the photograph is don't use the same color wire for everything.
.

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Well...... I had a few thousand feet of aircraft wire sitting in my garage. It has flame and abrasion resistant insulation and tinned wire - way better quality than what's available for boats. So it may be non-standard as far as the boating world, but is a step up in safety and durability. Plus, it's next to impossible to find striped color coded boat wire at anything close to a reasonable price.

Every single wire is numbered, and a laminated wiring diagrarm will stay in the boat (not that I ever expect anyone besides myself to ever lay hands on the wiring).