# 12 Volt 3-Way Panel Mount Switch?



## Proby (Jul 17, 2010)

OnThePike said:


> Thanks Proby.
> 
> So how does this work, exactly? The center position on the SPDT is the "common"?


Pretty much. I attached a diagram of a 3-way or SPDT switch.


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## Mr Chips (Mar 23, 2008)

i think the SPDT is the same ON/OFF/ON switch you are already familiar with. I have never heard of using 2 of these as 3 ways, but i'm not saying it won't work, just not sure

I have seen 3-way, 12v switches sold for RV's, but they are large, not like a small dashmount job


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## Proby (Jul 17, 2010)

Mr Chips said:


> i think the SPDT is the same ON/OFF/ON switch you are already familiar with.


A SPDT switch only has (2) positions.

If you go to Radio Shack's website and search for: SPDT you'll find a bunch of them. Try searching for: 275-648 That's a nice one that will work for you.

What are you going to be doing with this switch? How much current?


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## Mr Chips (Mar 23, 2008)

Proby said:


> A SPDT switch only has (2) positions.
> 
> If you go to Radio Shack's website and search for: SPDT you'll find a bunch of them. Try searching for: 275-648 That's a nice one that will work for you.
> 
> What are you going to be doing with this switch? How much current?


man, it's been a long day..... this should work fine. I'd make sure to use a fuse on the power feed going to the first switch


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## Mr Chips (Mar 23, 2008)

OnThePike said:


> Yes, I have seen them. If I was going that route, I'd just use whatever Levitton I have laying around.


switches rated for 120ac won't handle the direct current well. they are prone to arcing and other problems under direct current. so it/s probably a good thing that you don't want that look


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## Proby (Jul 17, 2010)

I know exactly what you mean about Radio Shack, I use Parts Express instead. 

Good luck with your project.


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## nap (Dec 4, 2007)

OnThePike said:


> I wasn't aware that a SPDT switch could be used as a 3-way switch. .


what you do is use the first switch as a standard switch (1 line/ 2 load terminals) but on the second switch, you use it backwards (2 line terminals/ 1 load terminal).

simply put; you feed hot_ to_ the "C" terminal on one switch and feed_ from_ the "C" terminal on the other switch to the load (light). Then you simply connect each of the unused terminals on each switch to an unused terminal on the other switch. Those are your travelers.
viola`, you have a low voltage DC 3 way.

I would suggest you power the first switch with a switched hot that would be hot in either "run" or "acc" on the keyswitch.


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## Mr Chips (Mar 23, 2008)

OnThePike said:


> Does anyone use spade bits on dash plastic?


i think just about everybody does


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## Proby (Jul 17, 2010)

I'd drill it front thru the rear. I don't think you'll have any issue.


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## Mr Chips (Mar 23, 2008)

OnThePike said:


> I'm concerned with a clean hole. There's only 2mm circumference of switch edge (ridge border). That means I only have 1mm to play with. Spade bits tend to drag material and rip edges on plastic.
> ?


You can always drill an undersized hole, and use a Dremel with the little drumsander bits to open it up a little at a time untill you get a good fit


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