# Cool wiring for running / anchor lights



## gnappi (Jun 23, 2018)

I got frustrated trying to find a commonly found, uncomplicated, inexpensive switch that I can buy most anywhere that can be used for an anchor / running light, and I also wanted some red / white LED courtesy interior lighting without having too many switches. 

The switch (shoreline marine SL51351 on-off-on ) I decided on is rated at 15 amps so if you're running low power LED's which will run in the low single digit current draw the switch is well within safe operating limits. Even old fashioned filament bulbs won't draw near that much current. If the switch should ever go bad a replacement is only as far away as a local Wal Mart.

I genned up the switch diagram below which is very simple to wire up. 

Obviously the current capacity of the diode should be selected to exceed the draw of either the bow or stern lamps, but I used a IN5391 6 amp, overkill yes but it's what I had lying about.

Notes: The switch LEDs both illuminate depending on whether one or both circuits are selected (but are off in the center position) and the jumper / diode connections are only made on the end terminals NOT the center DC in / feed wires. The diode acts as a simple steering diode which conducts in one direction and not the other.


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## richg99 (Jun 24, 2018)

Neat. I know who I am coming to for electronic information from now on.

Thanks, rich


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## DaleH (Jun 24, 2018)

... but now you cannot have a bow light & stern all-around light on at the same time, which is regulation.


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## richg99 (Jun 24, 2018)

*"but now you cannot have a bow light & stern all-around light on at the same time, which is regulation"*

Hmmmm when did they change that one?


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## DaleH (Jun 24, 2018)

For those 2 position switches, they are typically circuit A ‘on’ or circuit B ‘on’ or if wired correctly (with the blocking diode), there is a switch design that has circuit A ‘on’, and then circuit A + B ‘on’ at the same time, which would be typically used to run the nav (red/green) lights ‘on’ only or the nav lights ‘on’ with the all-around light ‘on’ at the same time. That is how I wire all my boats, as when night fishing I don’t like the white all-around light ruining my night vision.

Frankly, I’ve been wiring boats for 40-years and I’ve been using switches like that shown (1 - Off - Both) all the time, so I don’t understand why that switch maybe something ‘new’, as to me it isn’t, less the internal LEDs for which circuit is energized. 

But otherwise, yes, LED lights have changed the ampacity landscape and you can run more things on a given circuit ...


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## gnappi (Jun 26, 2018)

DaleH said:


> ... but now you cannot have a bow light & stern all-around light on at the same time, which is regulation.




Daleh ??? Splain me? That switch works just as you said, if it's wired as in my diagram. 

Dale, as far as other switches working, that's well known but. My quest was for a common DPDT center off switch that is available with or without internal LED's. A 360 on while running doesn't bother me at all, as I don't have a rear view mirror  

The rub with an on-off-on is you get *nav*-off-*nav+aft* (as shown above in the switch diagram) if you want to split some permutation of aft/masthead lights you're on your own, or just wire the two white lights in parallel or get a switch made for including an aft / masthead in the mix. .


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## wmk0002 (Jun 26, 2018)

Thanks for posting. I will probably do this when I wire up my jon boat. I have not had much luck finding an *Anchor ON - OFF - Anchor + Nav ON *switch locally and even the ones online are pricey. 

Do cheap, basic Radioshack diodes need any weatherproofing or protection from vibrations? I solder and heat shrink my connections but not sure about the diode itself.


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## gnappi (Jun 26, 2018)

wmk0002 said:


> Thanks for posting. I will probably do this when I wire up my jon boat. I have not had much luck finding an *Anchor ON - OFF - Anchor + Nav ON *switch locally and even the ones online are pricey.
> 
> Do cheap, basic Radioshack diodes need any weatherproofing or protection from vibrations? I solder and heat shrink my connections but not sure about the diode itself.



Dunno if RS ever had diodes larger than 3A like the 275-1144 (two pack 3A 400piv) I keep here. I used these to make full wave bridges for low current power supplies and if I needed larger than that I ordered online or went to a local ham radio supply house.

If you're using LED lamps those 3A diodes should work fine, I wouldn't use anything smaller... you don't want the diode acting as a fuse? Or, maybe some actually may want that? 

Anyway, since I used the solid axial lead (pre tinned) diodes and OFC wire, I crimped and soldered both into the yellow 12/10 gauge push on terminals. I always use a 1"- 2" length of heat shrink over my connections less for weatherproofing / vibration than for additional electrical insulation. If you're concerned about the terminal getting salt intrusion, extend heat shrink all the way up the male pin and shrink it and I guess some topical application onto the pin of some sort may keep corrosion at bay.

There's some controversy about crimp only versus crimp, solder, and heat shrink. but... for 19 years I lived on a salt water island with two boats tied to my dock, next to a large chlorinated pool and before that I lived many other years as a land locked ocean going boater and never had a connection that was crimped, soldered, and heat shrink protected fail for any reason. Every OTHER connection had issues long before I had to even think about my connections.


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## gnappi (Jun 27, 2018)

PS, since the diode leads are a short risk it's a good idea to heat shrink the whole diode, leads and all. Diodes are totally sealed and require no weatherproofing from moisture.


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## DaleH (Jun 27, 2018)

richg99 said:


> *"... but now you cannot have a bow light & stern all-around light on at the same time, which is regulation"*
> 
> Hmmmm when did they change that one?


*Change it? *Per ColRegs it has always been that way ... 

_Youse guys fishing local lakes & ponds don't need to worry _about ColRegs, unless maybe out on Lake Superior or something and there's a tug & barge in tow heading for you. But for fishing the salt, your r/g nav lights and all-around or stern light are to be 'on' at the same time.


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## LDUBS (Jun 27, 2018)

I was only kinda sorta following but now I think I got it. I was thrown off by the use of a diode. Then the light bulb (15 watt) switched on -- you did that so that you can have your anchor light on without the running lights. Do I have it right?


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## richg99 (Jun 27, 2018)

Okay. I mistakenly took the comment that "you cannot have etc." to mean that the regs had changed. Not the other way around. 

All is well. All on! 
rich


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## gnappi (Jun 27, 2018)

LDUBS said:


> I was only kinda sorta following but now I think I got it. I was thrown off by the use of a diode. Then the light bulb (15 watt) switched on -- you did that so that you can have your anchor light on without the running lights. Do I have it right?



Yup, you got it. When the aft light is turned on the diode blocks the +12volts from going to the bow light. When the bow light is selected ordinarily with a DPDT switch only the bow light would turn on. But with the jumper on the neg side and the diode connected with the anode on the bow light + side of the switch the diode conducts the +12 volt to the aft light also. 

BTW, the diode presents a .7 volt drop across it so if your battery was at 12.7 volts, the stern light would only get 12.0 volts fed to it which is more than sufficient to keep the light lit.


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## mbweimar (Jun 28, 2018)

This is the schematic I follow when wiring nav/anchor lights. It uses the same double pole double throw switch, and allows "one circuit on, or both on." This eliminates the need for a diode, and is one less component to fail.


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## gnappi (Jun 29, 2018)

mbweimar said:


> This is the schematic I follow when wiring nav/anchor lights. It uses the same double pole double throw switch, and allows "one circuit on, or both on." This eliminates the need for a diode, and is one less component to fail.



It looks like the standard OEM Carling type switch with 7 contacts, and your wiring diagram is well known and in use worldwide. No debate there. I almost went that route myself, but availability, practicality and to some extent cost ( like to keep spares handy for odds and ends like switches) were factors.

https://newwiremarine.com/product/nav-anc-rocker-switch-contura-ii/

My diagram can be made with *any* DPDT switch (though I like the lit Shoreline) and I fail to see how a properly selected diode will fail any more than a properly rated switch with a sufficient current rating. 

Then again the MTBF of a 7 pin switch also raises the failure rate by adding internal contacts, another pin and lug connections no? Split hairs? Not me 

Anyway... something else to think about with the switch itself being lit. If one or both of your anchor/running lights fail the confidence level of the switch and all the upstream wiring is unquestionably faster to diagnose an issue should you need to look into why lights are not working. Also in a remote location like a fly bridge (unlikely in a tinny no?) where the skipper cannot see all of the lights, the LED's on the switch are an excellent indicator of lighting status rather than peering around to see if something is working / running or not. 

Just IMO, and anyone who chooses either method has their own reasons.


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