3-Way Porch Light

[peterh]

One of the things we didn't like about the way Scamp did things is our porch light can only be operated by an outside switch. It would be nice, we thought, to set the light up so it can be turned on and off from either an inside switch or an outside switch.

To accomplish that I needed two "SPDT" (single pole, dual throw) switches, one of which had to be a match for the existing switch in the porch light housing. After browsing online for a few hours I found some (they came in a lot of six, so I have a few extras if anyone wants one). The interior switch was easier to find: it's a standard Radio Shack switch. The other supply I needed was a few feet of 4-conductor, stranded, 18-gauge alarm system wire (Home Depot).

The wiring diagrams look like this:





Here are pics of the exterior porch light. (Sorry about the ugly caulk . . . Still have to get that off one day.) The replacement switch is somewhat deeper than the original, so I had to bend the leads from the back of the switch forward toward the lens of the light to prevent them from short-circuiting to the aluminum backer plate of the light housing. The wires have all been soldered into place on the switches.





And the inside switch located on the side of the cabinet next to the door. It's the bottom switch.

[Doug Mager]

PLEASE SIR, May I have one (switch)
....for which I'll GLADLY repay you for on Tuesday (or at Taidnapam in June, LOL!!!)???

[Roy in TO]

May I have one as well?

PM sent.

[Steve L.]

Technically, aren't two SPDT switches required? The current switch is SPST and it needs to be replaced as well.

Oh wait, I get it. You've found a switch that fits the hole in the outside light fixture. Another SPDT switch of any convenient form factor is needed for the inside switch.

I've had good luck with nick-knacky type electronics supplies with Mouser.com. Searching for "SPDT rocker" finds 647 of 'em!

[Donna D.]

so I have a few extras if anyone wants one).

Me, me, me PLEASE. I've had a porch light sitting in a box for ever so long. I too didn't want to put it on the trailer until I had the solution for two switches.

You are a peach Peter! I'll see you and Lynn at one of the gatherings this spring/summer. I'll have cash in hand!

[Greg A]

PET PEEVE: Porch lights that are left on at night.
Just had another one do this next to us at Cottonwood last week. Ruined the stars and ambience of the beautiful night.

Hope once everyone gets their switches installed you use them to TURN OFF THE PORCH LIGHT once you're inside....

OK, my rant is over....

[Donna D.]

I 100% agree with you Greg. I think a lighted switch (inside) would be best. Green when on, no color when off (so it doesn't bother sleepers) at night, or maybe a dim red for off?

[peterh]

PET PEEVE: Porch lights that are left on at night.

I agree with you on that one, Greg, and since our porch light with the LEDs installed is even brighter than it was with a standard bulb it's even more important to make sure the light is off.

I considered installing a rocker switch with an LED that illuminates when the light is on, but that would have required yet another conductor wire to come back from the light, and I had already used all four conductors in the alarm wiring binder and didn't want to run another conductor back. Besides that the switch is right next to the door, it's pretty easy to look out the window to see if the light is on.

[Roy in TO]

Besides that the switch is right next to the door, it's pretty easy to look out the window to see if the light is on.

During the day you would have to stick your head out to see for sure.

I'm wondering if you could connect a single 12V LED indicator into the red positive line feeding the center terminal of the switch inside?

[peterh]

I'm wondering if you could connect a single 12V LED indicator into the red positive line feeding the center terminal of the switch inside?

I wired it up the way shown in my diagram because I needed both the 12v+ and 12v- leads for the amps/volts meter.

You could wire it up like this to power an indicator light, too.

[Roy in TO]

That is not quite what I was thinking. I don't have anything to draw nice diagrams like yours so bear with me:

You 1st set of diagrams shows:
[+ve]--red--[switch1]==yellowgreen==[switch2]--red--[light]--[-ve]

I am suggesting:
[+ve]--red--[LEDindicator]--[switch1]==yellowgreen==[switch2]--red--[light]--[-ve]

If I am thinking right, the LED indicator will only light up if both switches are in the right position to allow the electricity to flow. I hope you understand what I am trying to say.

So in your last diagram, the red wire would go into the indicator light, then back into the switch, with out connecting directly to the black wire.

Edit to add:
I just noticed you also changed the wiring at the second switch in your second diagram, my thoughts were that it would be wired like in your first diagram.

[Roy in TO]

If my elecTRICKical lingo is right, I am suggesting the LED indicator be wired in series where you have it wired in parallel in the second diagram???

[peterh]

Yes, my second diagram shows the indicator light wired "in parallel" witht eh porch light.

Per your suggestion you could wire an incandescent indicator light "in series" with the porch as long as both the indicator light and the porch light were incandescent bulbs. The problem with this set up is with both bulbs feeding off of the same 12v feed, they'd both be dimmer than if you wired them "in parallel."

If you used LEDs in series somewhere you'd have to do a little electrical engineering to get the right amount of current to pass through the LEDs to get them to light correctly and not burn out. LEDs are very picky about voltage and current, so it's not at all practical to wire an LED indicator light in series with the porch light.

[Roy in TO]

Ooops,
Does that mean I'm going to have troubles when I try to rewire my trailer with LED's and use the switches I bought that have the little LED indicators built into the buttons?

[peterh]

Ooops,
Does that mean I'm going to have troubles when I try to rewire my trailer with LED's and use the switches I bought that have the little LED indicators built into the buttons?

That depends. Most 12v "indicator light" switches have three posts/connectors: a line voltage post, a post for the wire heading off to the electrical load (the light or appliance), and a "ground" post, so it actually operates two circuits in parallel, th indicator light circuit and the load/appliance circuit.

[Roy in TO]

Yep, that's what I got, those will do for most my circuits then.
I'm hoping I can find something similar in a 3 way switch for the porch light then.
Thank you

[peterh]

After several people commented that they liked my installation, but would add an "indicator" light that would light up next to the switch when the porch light is on.

Lynne thought that was a pretty good idea, so . . .

I bought a pack of bright blue LEDs that had been pre-wired with a resistor for 12v use and wired it up. I didn't even have to cut a hole in the fiberglass for the indicator light! The LED is bright enough that I was able to mount it on the backside of the fiberglass wall so that it points outward, and the light is bright enough and the fiberglass thin enough that the light shines right through. So now we have our switch and an indicator light.





The LEDs came in lots of 20, so I have lots of spares. If any one wants one, let me know.

--Peter

[Doug Mager]

After several people commented that they liked my installation, but would add an "indicator" light that would light up next to the switch when the porch light is on.

Attachment 18513


The LEDs came in lots of 20, so I have lots of spares. If any one wants one, let me know.
--Peter

Peter, you ARE coming to the June Meet aren't you....? What about the one in Canada this May? In either event (if you come to one or either) bring two or three of these set ups with you. I know I want to do add this item to our Trillium too.

[peterh]

Peter, you ARE coming to the June Meet aren't you....? What about the one in Canada this May? In either event (if you come to one or either) bring two or three of these set ups with you. I know I want to do add this item to our Trillium too.

Doug, with all the things you want to talk to me about, perhaps I should describe myself so you can figure out who I am when we show up at the Washington State Gathering.

Truth is I look a lot like Donald Trump. I'm a little shorter and thinner and have dark hair and eyes and a medium complexion instead of blond, blue, and fair. I'm younger and usually more casually dressed, and I have a little more hair up-top, so I comb my hair differently because because I don't need a funky comb-over. Oh, yea, he has a funny Boston-New York hybrid accent, where mine is a funny British-California-Ontario mix.

That should make it easy to find me when we arrive.

[Doug Mager]

Doug, with all the things you want to talk to me about, perhaps I should describe myself so you can figure out who I am when we show up at the Washington State Gathering.

Truth is I look a lot like Donald Trump. I'm a little shorter and thinner and have dark hair and eyes and a medium complexion instead of blond, blue, and fair. I'm younger and usually more casually dressed, and I have a little more hair up-top, so I comb my hair differently because because I don't need a funky comb-over. Oh, yea, he has a funny Boston-New York hybrid accent, where mine is a funny British-California-Ontario mix.

That should make it easy to find me when we arrive.

......ROTFLMBO!!!