Wiring diagram for an O/B.

I've started the wiring process in an outboard boat that I'm completing. I've purchased a surplus wiring harness and split all of the wires out and sorted by color. I'm hoping to have the whole electrical system colored to industry standards.

I've drawn up the wiring schematic and put it in JPG format. Hopefully, some of you will be interested in looking at it and can tell me if I've errored anywhere. Ultimately, I would like to put it in the electrical WIKI here for the benefit of others.

Some of the colors might be off, but ultimately, it's the connections that are important. Currently, the diagram is drawn with an ammeter. I'll be switching that to a voltmeter, with the correct wiring for a voltmeter.

The power distribution box forward is a fuse box or C/B panel. I'll have to work on annotating the drawing.

Looking forward to hearing your input.

 

Simplified wiring diagram of charge circuitry.

I'm still interested in getting feedback on my wiring diagram. I can understand the lack of response as my own eyes start to glaze over when I start looking at somebody elses wiring diagram.

I have hidden all extraneous circuitry and only left the power/charge circuitry. Hopefully, some generous soul will take a few minutes to see if there are any mistakes in my power/charge circuitry. I've also switched to a voltmeter with the associated wiring.

Thanks again for any input.

 

Just a few remarks:

-You have the bow light wired to the stern light, but not to a switch.

-Why are there 4 leads to each instrument? If they are illuminated you can connect both the instrument and the bulb to the switched +.

-As far as I know there is no industry std color scheme. Each manufacturer has it's own standard: the French even dare to use RED for Ground!

 

Thanks for your input CDK.

The four leads to each instrument are; (+), (-), illumination and signal. I could run the illumination from the (+), but I want the option to turn them off. More than likely, I'll wire them to the nav lights since that is when I'll need them.

Speaking of nav lights, yup, I did not connect the switched nav light lead to the nav light wire. Oops! Brings up the fact that I need an anchor and a nav switch position and circuitry. Another Oops!

I've got an Excel spreadsheet that I've put together with color codes. It's just a cut and paste job from about four different sources. It appears that there is some standardization as the sources correlate fairly well. I didn't document the third and forth sources. I've attached it.

 

You'll probably find you will have to update on the diagram some more. There are always afterthoughts (oopses) to compensate for. In hard to get places it may be a good idea to add some extra wires.

The best way to do the wiring is to keep it simplified.

 

Neutral safety switch?

 

Update

Here is an updated diagram.

I added a kill switch to isolate the ignition circuitry. My goal was to be able to run electronics with the engine off and this looked to be the simplest way. It's a safety feature, too.

Added horn, courtesy lights and leads for possible stereo and fish finder.

Ran the the ignition and start leads to throttle quadrant for possible neutral safety and kill switch connections there.

I think that covers it for now.

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It doesn't show very well, but a drew a diode at the nav/anchor light switch to isolate the anchor light circuit. Is that typical or is there a better/safer way of doing it?

 

Do consider one battery dedicated for starting the motor and another battery for running the accessories. This way you will always have a fresh battery for starting the motor.

 

This looks pretty good and if you ran it this way it should work!

The things i noticed. . .

Tank should be grounded to the negative buss (w/green)

No temp gauge / sender?

No over temp / low oil sender for "idiot" buzzer?

Alternator output usually runs directly to main starter positive connection on the engine

Ignition switches seem wonky, usually purple is ignition on, yellow with red is starter solenoid.

Fuses? assumed they are located in the "switched buss" the main cable feeding this buss should be fused as well.

Some horns draw lots of power and they need a dedicated power source that is swithed with a relay, so the horn switch does not have to carry the full current.

Good luck!

Tony

 

There is a standard color code used by the industry; see http://newboatbuilders.com/pages/elect5.html

 

The longest wire on an outboard motor cant be more than a meter. If you have to buy coils of 50 meters then your going to have a lot of wire left.

 

Updates

Thanks all,

With regard for Tony's remarks. All good questions and comments, I should add (as are everyones).

I ran the ground from the filler to the tank and assumed the negative(ground?) from the tank would suffice in grounding those components. Perhaps, its just the color coding we are talking about.

This is going to be an outboard setup and right now I'm in the process of getting the motor to determine what type of leads and sending units it will have. I will add or subtract the circuits as neccessary.

I wondered about the alternater wiring. I ran across a wiring diagram that had an ammeter in the system and had originally wired an ammeter. (See the first post.) Switching to the voltmeter, I cut the wire back to where it is now. To me it looked like it wired the way you stated, but I hadn't the question yet.

You are correct. The switch buss is a fuse buss also.

The horn info is good to know. I'll be sure the check the horn specs when I get it.

Again, thanks to everyone for their thoughts and insights.

The progress continues.

 

Protecting the main feed.

Tony mentioned fussing the main accessory feed to the forward breaker panel.

I need a clarification regarding the position of this breaker. Someone correct me if I wrong, but I'm thinking that the starter circuit is essentially a straight shot(no fuses, no breakers, just the main battery switch) battery to starter solenoid.

In my mind, I would split the main accessory feed and starter feed at the downstream side of the the battery switch and fuss the main accessory feed at that point. Does this sound logical?


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Updated diagram to included the changes mentioned above. Added forward ground buss. Changes to account for wiring cable from speedo sending unit.

 

Normally the starter circuit is not fused. The inrush current when you turn the starter over would blow it unless you had an extremely large fuse, and since the only time it carries current is when starting you really don't need one.

 

Thanks, Ike.

The wiring aspect of my little project was initially very daunting. This little exersize in drawing up the schematic has brought everything into perspective and removed the OMG element from the whole equation. I should be wiring my project in the near future.

Thanks to everyone for their input!