I have a room downstairs with two light fixtures that operate off of a pair of 3-way switches on opposite sides of the room. The breaker these lights are on has other receptacles and lights on it as well.

Last week I bought a ceiling fan and put it up in place of one of the light fixtures. It was very simple - I took the old fixture down put up the handy ceiling fan brace & box between joists then hooked black to black white to white and then bare copper wire to green wire on fan.

This was a week ago today and now nothing on this circuit will work! Every switch has power to it and outlets have power but if you plug something into outlet, nothing!! When I plug Klein Tools RT100 outlet circuit tester into outlet it lights up to indicate hot/ground reverse??!! The house is about 46 years old and that’s how old wiring is as well. I've already checked every box on this circuit and there are no white wires out of place. Actually there’s nothing out of place because the only thing I done was exactly what I explained above and as I said everything was working fine up until this morning!

Can someone please help me with this!! Thank you.

  • 3
    When you wired up the fan did you act under the belief that white always connects to white and black to black? This is not true. The fact is that all neutrals are white, but white can be used to carry hot to a switch. And formerly white was often used for a switched hot from a switch to a light fixture. Sep 15, 2019 at 12:05
  • 4
    Did you take a picture of the wiring you took apart before you took it apart? You should have. Just about guaranteed one of the white wires was not connected to the others. Which one matters, a lot. When dealing with old switch loops I mark those with red tape (they should have been marked red or black when installed, but rarely is that the case.)
    – Ecnerwal
    Sep 15, 2019 at 13:22
  • 2
    Can you post photos of the insides of all boxes involved? Sep 15, 2019 at 13:45
  • Is there only one cable in the ceiling box, i.e., one black one white and one ground, all in one cable? Or is there more than one cable coming into that ceiling box? Sep 15, 2019 at 17:21

3 Answers 3


I would access the fan wires again, and using volt meter, check from black to ground and white to ground, if you have 120v from white to ground that is your hot leg, now if black and white show 120v to ground I can only assume that one is a traveler leg since you have multi switches that can turn lights on and off from either side of the room

  • Hello, and welcome to Home Improvement. Thanks for the answer; keep 'em coming. And, you should probably take our tour so you'll know how best to contribute here. Sep 16, 2019 at 2:32

If I understand correctly:

This was a week ago today and now nothing on this circuit will work!

  • everything was working fine up until this morning

that would seem to indicate that none of the wiring you did was "really messed up" because if so, the problems would have started as soon as you installed the fan. **Please confirm that the fan, light, receptacles ALL worked from "fan installation" until "this morning".

Assuming that is the case, there are a few possibilities:

  • Something lose somewhere.

That can cause any number of different problems. The logical place, of course, would be any places that you recently worked on (i.e., the fan connections) but could be anywhere. Every wire should be connected with a secure wire nut or a screw. Check every box - fan, other lights (though depending on how the other lights are installed, that may not be so easy), receptacles, switches. If you find any loose wire nuts replace them. If you find any "taped only" connections, replace with wire nuts. If you find any "backstab" connections, replace with screw connections or, if no extra screw connections available (don't double-up wires on screws), add pigtail wire nut connections instead. Check (loosen and tighten if not 100% sure) every screw connection.

  • A reverse or bad connection somewhere

The RT100 test showing hot/ground reverse is quite troubling. Hot/neutral reverse is common if someone simply gets black & white reversed when connecting to a receptacle. Hot/ground reverse should never happen as ground wire (= green or bare) is quite distinctive and the device connection (green or bare wire or green screw) is also quite distinctive. Check the tester in a receptacle on a different circuit - if it shows problems elsewhere then you either have "a big mess" or quite possible a bad tester. If it shows correctly elsewhere then that is another data point but it does not necessarily mean a simple "hot/ground reverse" as combinations of miswiring in multiple locations can result in almost anything being "diagnosed".

All that being said, yes, a miswire where the fan is connected could cause strange stuff elsewhere, particularly if unswitched hot is being passed through the fan (formerly light) junction box.

Try disconnecting (cap with wire nuts for safety) ALL wires in the fan box. Then see what does/doesn't work. You may well find that now some places that had power before have nothing now - including possibly the tester showing different results.

Beyond that, it depends on what you find. Anything more than two blacks and two whites in the fan box (except grounds, of course) is an indication that there is more going on here than a simple string of switched light fixtures. Pictures, as noted by others in comments, will help a lot.


If you only had 2 wires at the fan fixture I would look for a open neutral. This is quite common and those testers get confused sometimes. The most common source of an open neutral would be at a back stabbed outlet that was used in a daisy chain. The fault will normally be at the last working outlet or the first non working one in that chain. It is possible that the neutral in the breaker box is loose, I have found neutrals doubled (a code violation) that came loose. It is league if the panel is rated for it to double even triple the grounds for a listed panel.

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