I have a switch to my hallway by my garage. The other switch is by my stairs. I have had a motion sensor on the switch by the garage for about 15 years and it worked fine.
It finally broke so I replaced it and now the new one will not work. I cannot even use the manual switch to turn it on and off.

I bought a cheaper one (about $17) whereas the previous one was around $30. Is it possible that some switches are not designed to be part of a pair? How can I tell? I don't mind getting the $30 one, but I wanted to be sure.

The behavior is that if I use the non-sensor switch, I can turn the lights on and off in the normal fashion. But the motion sensor switch just acts like it doesn't work, no matter what position the other switch is in. I do see the blinking blue light telling me the motion sensor switch is working, but it doesn't. I have double-checked the both wires and the ground. All are connected solidly.

Am I wasting time? Are some switched just not designed to work in pairs?

  • 1
    What make and model is your new motion sensor switch? Also, can you post photos of the insides of the boxes? Sep 10, 2018 at 0:01
  • Since your old setup had two locations where switches could control the light, you have what is called a "3-way" switch configuration. You can't use any random switch for that, you have to use ones made to play well in 3-way circuits. Sep 10, 2018 at 0:38
  • 1
    you would be better off getting a smart outlet and switches, then you have WAY more flexibility than trying to track down parts to meet a very specific set of hardware constraints.
    – dandavis
    Sep 10, 2018 at 18:24

1 Answer 1


Your switches and lights are wired in a "three way" configuration, so you need a three way motion sensor switch.

For example: the Eaton OS306U, although there are a variety on the market and they do start around $22.

Important things to note:

  • You probably need a model rated for "No Neutral Required", depending on the wiring to that box by the garage.
  • If you use Florescent or LED lighting make sure that the switch is rated for it (most newer ones are).
  • Make sure that the switch is rated for the lighting load you have. Most such switches are rated for 5 amps / 600 watts. If you have more light than that, you need a pricier switch.
  • It sounds like the current switch might be miswired. Consult an electrician if you are not 100% sure.
  • Good photos of the switch and wiring, posted in your question, help us give more specific and tailored answers.
  • Yes, I figured this out reading. I had a switch that was not enabled for three way. I bought one of those and all is well. Thanks! Sep 11, 2018 at 3:22
  • You're welcome; glad you got it working. Sep 11, 2018 at 4:03

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