wtf wiring problem - 3 way switches

DrPizza

Administrator Elite Member Goat Whisperer
Mar 5, 2001
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I hate these logic problems.

Two switches, I'll call them A and B. Both are 3-way switches. (either switch will turn a light on or off.) 2 fans. Fan 1 and Fan 2

Fan 2 has never worked. I replaced it today (got a display model at 1/2 price), and sure enough, when I took it down, one of the wires was loose.
So, I installed the ceiling fan (a clearance that had been the display model on an endcap)
It didn't work. I blamed the fan.

Long story short, here's where I'm at now. In the electric box for ceiling fan#2, the white wires were together with a wire nut, and both were wrapped with black electrical tape. The red wires were wire nutted together, and the black wires were wire nutted together.

Toggle either switch, and ceiling fan 1 turns on and off. HOWEVER, when ceiling fan 1 is on, there is no power to ceiling fan 2. No pair of the 3 wires shows 110V potential difference (I haven't checked against ground yet; I'm going to run out and get my multimeter from school in a few minutes.) But, when ceiling fan1 is turned off, suddenly, I have power to ceiling fan 2. i.e. toggle either switch and one turns on while the other turns off, and vice versa.

However, inside electrical box #2, if I separate the white wires while ceiling fan1 is on, ceiling fan 1 turns off. If I separate the black wires while ceiling fan1 is on, ceiling fan 1 turns off. But, there isn't 110V potential across the two. (As tested by sticking a lamp between the two wires; my cheapy electric tester is untrusted and doesn't seem to be working. AARRRGHHHH! both fans are (obviously) on the ceiling, and the switches are located at either end of the room. If it was wired with the two boxes between the ceiling fans, then there'd need to be a 4-wire cable (else 2 2-wire cables) between the two electrical boxes. But, the one I'm working in only has the two 12-3 w/g wires. Now, since one of the wires from the old ceiling fan was connected to the ground, I'm left wondering if the contractor who installed the wiring in that addition cut a corner.

This is going to take me forever to trouble shoot. I have no clue what the actual path is that the wiring takes.

If worse comes to worse, I'll just swap out one of the switches for a normal switch, eliminate the other switch, and ignore the carrier wire. But, it'd be nice to have the 3-way switch.

Anyone have any educated guesses?? (Heading out to get a multimeter; checking the thread when I return.)
 

Fritzo

Lifer
Jan 3, 2001
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Don't ask me. Last time I wired a 3 way switch, when you flipped it the toilet would flush.
 

Leros

Lifer
Jul 11, 2004
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I was under the impression that a 3-way switch as three options (turn A on, off, turn B on).
 

DrPizza

Administrator Elite Member Goat Whisperer
Mar 5, 2001
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AAAAAAAAAAAGHHHHHHHHHHHHHHH!!!!!!!!!!! wtf????!!!

Looked in the garage. Ahhhhh, there's a 12/2 and a 12/3 going into the switch. That's where the power comes from.
Looked at the other switch. There's also 12/2 going into it as well as the 12/3

Upon closer look, it only looked like there was a 12/2 in the garage electrical box. Two switches in the same box. Really, though, would it have been that hard to line that wire up with the half of the box that it goes to?
 

DrPizza

Administrator Elite Member Goat Whisperer
Mar 5, 2001
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Figured it out. Someone used the ground wire as the neutral, rather than running two cables. Farewell 3-way switch. No longer will I be able to turn on those lights from the garage. Yet another screwed up circuit in the house. (I'm rewiring the majority of the house, little by little.)
 

Greenman

Lifer
Oct 15, 1999
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It could be wired a couple different ways. The simple method would be to wire one fan on the three way switch then just have a jumper from that fan to the other one.
To trouble shoot the problem, figure out which fan is first in the circuit then take the other one out of the circuit. Get that one fan to work on both switches then add the second fan on to those same wires. I'm assuming you want both fans to come on at the same time. It shouldn't be that tough to get it working, and the diagram that comes with most switches should help.

It's tough to visualize what you have from the description.
 

DrPizza

Administrator Elite Member Goat Whisperer
Mar 5, 2001
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Thanks, Greenman,
I got everything working. I simply gave up on the 3-way switches. We almost never used the switch in the garage, so now it's not even connected. By separating all the wires, I figured out that both fans were between the two 3-way switches in the circuit. There's simply no way to do that with 3 wires between the fans. 4 wires are needed. They were using the ground wire as a neutral wire, AND as a ground wire! (the boxes were grounded too.) Too dangerous for my tastes.