I have a 3 way switch connected to a chandelier which is somehow not getting power. All the light bulbs work, but none switch on.

I know it's getting power because an electronic timer connected on one end of the three way switch still works—I went to the breaker and flipped all the switch... no luck.

Is there something missing in how I'm going about diagnosing this? There are no GFCIs anywhere near this.

Update: The non electronic switch has continuity across the terminals regardless of switch position, and does not have voltage regardless of switch position. Does this sound possible? Just a broken switch or is this normal for 3 way switches?

Update 2: Thanks for the comments. Below are pictures.
3 way switch side one
(It now seems obvious I had continuity across this side, but the switch seems to function well when continuity is checked against the other side.)
The other side.

I only have 9 volts across the switch when on, this is confirmed at the other end of the circuit the other end.

  • Did you remove the wires from the terminals when you tested the switch for continuity? Mar 26, 2018 at 9:58
  • There are timers that still work when the power is off. One specific example that comes to mind is Intermatic SS7C that has an LCD display. That timer runs on AA batteries. So arguing you know there’s power because the timer works could be a fallacy.
    – Tyson
    Mar 26, 2018 at 11:06
  • Can you post photos of the insides of the boxes involved? We don't have remote X-ray vision out here... Mar 26, 2018 at 11:38
  • Thanks of the comments, I added photos. No, the timer does not have a built in battery. I only get 9 volts on my multimeter (but 120 on other switches and outlets on the circuit).
    – wizlog
    Mar 26, 2018 at 15:04
  • This 3-way switch complex was already broken when you started this thing. Now you are adding more complexity and just ignoring the pre-existing problem and hoping it'll get out of your way somehow. If that doesn't work, roll it back to plain old 3-ways and get them working properly before proceeding further. Mar 29, 2018 at 20:58

1 Answer 1


Looks like 3-way being excluded and controlled only by the timer. If you want to make it work again, check connections to the timer and, if needed add a relay (1pole 3 contacts) to behave as second '3 way' switch andremove the 'bridge'.

PS: It is normal that the two 'deviated' poles on a 3 way are always disconnected from each other as the commute is between common and one of the 2 poles.

So these are schemas on how 3-way work (1), how 3-way with timer should be wired (2) and how your system is (probably) wired (3):enter image description here, enter image description here

  • How would I modify this for a timer which came with four wires? White, black, blue, red? It's replacing the one in my last picture which only had three.
    – wizlog
    Mar 29, 2018 at 6:03
  • You should post a schema (picture of timer output description, usually printed on timer itself, or link to online user manual) of what each timer cable does. Aniway: black and white should be the 'feed' and white is neutral and black is phase, for red and blue I can't say surely.
    – DDS
    Mar 29, 2018 at 8:39
  • Note the screw colors, the jumper doesn't short the two travelers, it shorts common and 1 traveler. Mar 29, 2018 at 20:51
  • It's possible (screw seem to be yellow), anyway the effect is the same: switch is by-passed. The difference between OP setup is that if the switch 'fails' the timer still turn on light, with my schema if switch fails, the light wont lit (even if timer is on). Sorry but I'm used to european stuff and wiring is little different (travelers top and bottom, common half-way)
    – DDS
    Mar 29, 2018 at 23:49

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