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Wiring Nav Lights with 3-way DPDT

Posted: Fri Aug 07, 2015 8:34 pm
by mobbs
Hello folks, quick question (hopefully) about wiring. I'm not very good with electrical stuff, so there's your disclaimer. Anyhow, I am working on replacing the switch on my pontoon that works the navigation/anchor light. The switch I bought is a DPDT 3-way on/off/on switch which lights up when in either "on" position. I wired everything up the way I believe was correct, but it's not working as intended.

When the switch is in the upper on position, the navigation lights up front are supposed to be on as well as the anchor light in the back (this part doesn't work).
When the switch is in the off position, everything should be turned off. (this part works)
When the switch is in the lower on position, only the anchor light should turn on. (this part also works)

As I mentioned, the part that doesn't work is when the switch is thrown in the on position for the nav lights. The LED lights up as it should, but only the front bow navigation lights turn on, the anchor light does not. This is confusing to me because it was a rare occurrence for the switch I am replacing to actually work, but when it did, all of the lights turned on as intended. I have not changed anything about the wiring to my knowledge and even bought a replacement switch that has the same amount of posts as the original switch. What's gives? With this new switch, is it simply a matter of splicing a wire off of the working anchor light wire and into the nav light wire? If I have to do this, why did it work before and it doesn't now?

Anyone have any ideas? This is amateur electrical work I think, but as I said, I'm not very good with this sort of thing. Below I have attached pics of how I have this switch wired up and the hopefully accurate labels for each wire.

Re: Wiring Nav Lights with 3-way DPDT

Posted: Fri Aug 07, 2015 9:27 pm
by HandymanHerb
That ground is for the light in the switch, so make sure all your lights are grounded to the battery

Re: Wiring Nav Lights with 3-way DPDT

Posted: Sat Aug 08, 2015 3:22 am
by TDJ2591
I'm no electrician but wonder if you have a simple on-off-on switch. It would switch either-or but not both. It may look the same as your old switch but differ internally.

Re: Wiring Nav Lights with 3-way DPDT

Posted: Sat Aug 08, 2015 7:02 am
by litgrep
Could you have your power plug and you anchor light switched? That would only light your anchor light when switched.

Re: Wiring Nav Lights with 3-way DPDT

Posted: Sat Aug 08, 2015 9:42 pm
by mobbs
I already tried switching the anchor light and power plug and one of the LEDs on the switch itself just illuminates but none of the actual nav lights or anchor light turn on.

Re: Wiring Nav Lights with 3-way DPDT

Posted: Sun Aug 09, 2015 11:57 am
by mobbs
Ok so I just found out that the switch is actually A SPDT 3 way on/off/on, not A DPDT. Could this be the issue? ?

Re: Wiring Nav Lights with 3-way DPDT

Posted: Mon Aug 10, 2015 8:19 pm
by rbtnt
You can add a diode between the nav wire and the anchor wire or install a dpdt switch.

Here is a link to the wiring.

https://www.google.com/url?sa=i&rct=j&q ... 9456775848

Re: Wiring Nav Lights with 3-way DPDT

Posted: Tue Aug 11, 2015 7:35 am
by litgrep
Make sure your Nav lights are working without the switch. They may have lost return. Wire positive 12 vdc directly and mack sure they lite with no switch. Then with an ohm meter find the two poles that short together switched to Nav and connect your 12 v though them.

Re: Wiring Nav Lights with 3-way DPDT

Posted: Tue Aug 11, 2015 12:57 pm
by Tlowry
mobbs wrote:Ok so I just found out that the switch is actually A SPDT 3 way on/off/on, not A DPDT. Could this be the issue? ?
Like rbtnt says, either of these will work but with a SPDT you will need the setup on the right using a diode.

Image

Re: Wiring Nav Lights with 3-way DPDT

Posted: Wed Aug 12, 2015 8:55 am
by mobbs
Thanks folks! Exactly the help I was looking for!