[MattDice]

Hey guys,
I'm pretty comfortable/knowledgable working with electrical and I understand the basics on how 3 way switches operate and have recently wired up a brand new 3 way switch for some recessed lighting in my own house.

Now I was helping the in-laws out by installing a new ceiling fan in their bedroom tonight and ran into a head scratcher. They insist that the fan was on a 3 way switch with 1 switch by their bed and 1 at the rooms door. Now the old/new fan as no light kit installed, just a fan. When I took the old fan down the only wires coming out was your standard red/black/white ground 14-3, or 12-3 wire (I didn't check that). Simple enough...wrong. Using my voltage tester I determined that the red/black wires were always hot no matter what the switches they claim operate the fan did. So I opened up the switch boxes to see that both switches had 1 red/black/white connected to it. In one of the switch boxes there were 2 switches that are 3 way switches with only 2 cables coming into the box, 1 cable going to 1 switch. The way I've wired a 3 way switch I would expect to see atleast 4 cables coming into the box, 2 for each switch.

If I wired the ceiling fan black - black, white - white, red - blue, ground - ground, the fan would run but was not controlled by any of the 2 switches and that is where I stand right now. I'm really confused by this and would like to know why the heck a 3 way switch is wired this way and how it works.

Any help would be appreciated.

Thanks,
Matt

 

[frenchelectrican]

I have a huntch that the oringal switch was wired for single pole and someone add a three way switch which you stated that you have red et black et white on that switch that we called three way switch loop { end of run type }

The key item you have to look for is the common on the end loop is typically a darker colour screw or marked common the brighter brass screws are shuttle or travellers.

Go to the oringal switch box and make a note how it hook up I will post a diagram in a second.

I think this the one you have

Just watch out the white conductor on the switch side and I am very seriously you remark them before you do anything else more on the three way loops so you know that is not a netural. this only used with the cable but if you have in conduit { pipe } then just pull in a correct conductor colour in there.

So let us know what ya got there and read the diagram if that not the correct one let us know one of us will post the other type of diagram.

Merci,
Marc

 

[MattDice]

Marc,
Thanks for your reply. I'll go open up the switch boxes later today and get a deeper look at them like you suggest and report back what I find. What would be the reason the switches don't work on the wires coming into the lightbox? Especially since I have not messed with the switches and just taken down the old fan?

Thanks,
Matt

 

[jcrack_corn]

someone may have wired it as a switched neutral, which is considered unsafe.

figure out whats going on and correct it immediately (imagine turning the fan off from the switch and then taking it down, assuming the wires were dead, when in fact they are hot, as you found, due to a switch neutral ---- even thought he light and fan are not on) ---- people are very used to positive (+) and negative (-) regarding voltage and have a tough time understanding how A/C flows and how "off" can still be dangerous.

 

[MattDice]

Thank you everyone for your help. I went back today and figured it out. The black wire in the ceiling box is always hot, the red was connected to the switches.