New outdoor GFCI box installed from existing indoor receptacle, plus new LED motion sensor installed from GFCI box, plus plug-in timer device for patio lights. Will motion sensor timer and plug-in timer both work from this new box?

The plug-in timer is a Defiant model TM142DOLBD while the motion sensor is either a Heath/Zenith 5312 or 5318, not sure which.

The timer did go on at dusk but did not turn off in 2 hours as set. It stayed on until dusk. Since timer and motion sensor both have a timing feature, could they be incompatible when used on same receptacle or circuit?

  • What make and model are the motion sensor and plug-in timer? Jul 22, 2017 at 15:17
  • @user73370 Please merge your guest and registered accounts, which will allow you to edit, comment on any of your posts and accept an answer on your question. Thanks, and welcome to the site!
    – Niall C.
    Jul 23, 2017 at 18:28
  • ThreePhaseEel, any ideas?
    – Diane
    Jul 24, 2017 at 19:49
  • Are you trying to connect them in series, or independently of each other? Jul 25, 2017 at 11:46
  • Handyman installed outdoor gfci that taps off indoor receptacle, then ran conduit up siding for new motion sensor light. I plugged new Defiant timer into gfci receptacle for some patio lights. Defiant timer did not work right, reverted to Dusk-Dawn regardless of dial setting, whether I put it on 2 hrs, 4 hrs, etc. I bought another new timer, thinking it was faulty, tested this new one on different circuit first. It worked right, until I plugged it into the gfci receptacle. Wondering if motion sensor timer is wired differently than Defiant timer and so are incompatible if on same circuit?
    – Diane
    Jul 25, 2017 at 20:46

1 Answer 1


The shutoff time for the Defiant timer plugged into the GFCI should not be affected by anything other than what time it senses dusk.

  • I would think that would be the case. So I assumed the timer was faulty, though brand new. I bought another new one and it also did not function properly with respect to shut off time. Polarity supposedly checked out fine per handyman testing. All I can think of is internal wiring of devices being different so incompatible. Totally at a loss with my limited knowledge. Handyman not much better.
    – Diane
    Jul 26, 2017 at 4:17
  • Is it possible that there is some visual interaction between the lights (or others)? If the motion-sensor light shines on the timer sensor long enough, it might trigger a "dawn" reset, restarting the "dusk" conditions when the sensor-activated light times out.
    – Upnorth
    Jul 27, 2017 at 14:49
  • The motion light shuts off in 5 minutes. The small string of patio lights is around the corner of house from where plug-in timer is situated, so no light shines near the timer. But good thought, thanks! Do you know whether dial-set timers have electronic ballasts? And do motion sensor lights have them? Would/could a ballast even affect my issue? (Reaching at straws, maybe, but can't get off the concept that differences in the devices' timing mechanisms may be responsible if drawing from same receptacle.)
    – Diane
    Jul 27, 2017 at 17:43
  • Plug-in timers are typically very simple devices having no need for a ballast.
    – Upnorth
    Jul 27, 2017 at 20:42
  • Bought a third new plug-on timer, Woods brand instead of Defiant. Package says electronic ballast. Defiant dialset packaging does not mentiin ballast at all. The digital Woods brand timer works! That's why I need to know if simple fact of not having ballast is the answer to the Defiant fails on this particular circuit with motion light, or could I have a totally different electrical problem and need to keep looking in case handyman wired new gfci improperly. Or even maybe something else is wrong in my system, not caused by handyman, only revealed by his work?
    – Diane
    Jul 28, 2017 at 16:48

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