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I'm replacing my current lighting with a new fan. The existing light was attached to a dimmer switch, and I'm putting in a conventional switch since a dimmer would damage the fan. I opened up the old switch and inside is a red and two blacks joined together and attached to the switch. The existing light has two cables going to it, each with a black, white, bare copper, and one cable has a red. The red is connected to one side of the light wiring, the whites are bloomed together and to the other side, and the blacks are joined together. Bares are joined and pigtails to the box.

I'm not sure if the excess wiring had to do with the dimmer or what, but the new fan only calls for one supply, neutral, and ground.

Not sure how to proceed. Thanks!enter image description hereenter image description here

  • Could you please post pictures of the switch box wiring and the ceiling box wiring. – bib Jun 14 '18 at 20:47
  • Sure, I attached the switch inside and and cables at the fixture after they were all taken apart. The picture from before pulling them apart was too big to upload. I took them apart simply to remove the box, figuring the fan would have one but it doesn't so I probably didn't need to, but nothing really lost there – RossoCarne Jun 14 '18 at 20:57
  • Side note, there are also joined white and joined ground inside the switch – RossoCarne Jun 14 '18 at 20:59
  • See the scorch marks on the red wire? Backstab. – Harper - Reinstate Monica Jun 14 '18 at 21:28
  • I'm glad you pointed it out, I don't have an eye for those things – RossoCarne Jun 15 '18 at 12:11
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Make sure you install a proper fan support junction box that attaches firmly to nearby joists. A regular lamp ceiling box cannot handle the dynamic loads (vibration etc.) of a fan. An "old work" ceiling light box that merely clips to the drywall would be totally inappropriate. Drywall has no real strength.

I don't know whether power comes into the switch box and onward from the fan; or into the fan and onward from the switch box. Regardless, the wiring is the same. Also, it's a rare situation where all wire colors match their purpose, so color coding does work here.

  • All grounds are tied together. Each device gets a ground pigtail, i.e. there's a wirenut in the box joining all the grounds.
  • All neutrals are tied together. Each device that needs neutral (the fan) gets a pigtail.
  • Black is "always-hot" in all cases, and all blacks are tied together. Each device that needs always-hot (the switch) gets a pigtail.
  • Red is "switched-hot". One end goes to the switch. The other end goes to the fan as its "hot" wire (typically wirenutted to a black wire on the load).
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    There are "old work" ceiling fan boxes -- these use a crossbar that's tightened against the joists on both sides of the joist bay – ThreePhaseEel Jun 15 '18 at 8:02
  • When I took the box out there was a support. That's why I took it out in the first place (forgot when I mentioned it the first time). Either way the advice was spot on, Thanks! There was also a piece of wire broken off in the light so that needed replaced but I got it working. Thanks! – RossoCarne Jun 15 '18 at 12:14

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