Here's one for the master electricians.

I just installed two new LED down lights and noticed this morning that when I turned them on they started flashing on-off at about a 1sec cycle.

When I installed them this was not the case, but I did notice that these lights (600 lumen) appeared to be rather dim... However this is my first set of LED down lights and so I wasn't sure if this was just their normal state of being.

The wiring is straight forward, I junctioned a 120v line that appears to feed power from the master bedroom to a spare. The junction runs to a SPST switch (non dimmable) and the runs from the switch to light #1 then to light #2 in series.

Now here is where it gets odd. I've discovered that if I turn off the lights in the master bedroom the new LED down lights flash! And if I leave the master bedroom lights on the LED down lights are steady but they are dim!


How do I get these new lights to start acting normal.

  • Low voltage can do this; check your connections. Overheating bulbs can also flash, as I rather annoyingly found out this week; one of my Cree bulbs has become more temperature-sensitive as it has aged. (Admittedly I was using it in a fixture that was trapping more heat than the manufacturer would have approved of.) – keshlam Oct 4 '15 at 14:42
  • New discovery. When I turn off the master bedroom lights but leave the new lights on all lights flash! The master bedroom and the down lights! – Chris Heller Oct 4 '15 at 15:17
  • You said that you have the new lights wired in "series". Did you really mean that? If so, that is probably your problem. All line-voltage fixtures are wired in parallel (that is, hot wire to hot wires of all fixtures and neutral wire to neutral wires of all fixtures). – DoxyLover Oct 4 '15 at 15:28
  • Sorry no I meant that the hot goes from the switch to the first light to the second and the common and gnd do the same. – Chris Heller Oct 4 '15 at 16:04
  • A clue. The master bed lights are tied into a three way switch. One end is a dimmer. I removed the dimmer switch and tied off the wires. Now the master br room lights work but my new down lights are without power. But the lines they are tied into are still hot. – Chris Heller Oct 4 '15 at 19:47

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