I recently had to re-wire a three-way switch. What I found on arrival was that when the first 3-way was down, the second 3-way would turn the fixture on and off.
When the first 3-way was up, the fixture would come on and stay on regardless of the position of the second 3-way.
There was nothing unusual about the wiring: Feed at first switch; 12/3 carrying the neutral and two travelers to the fixture; neutral ties to the fixture; 12/3 continuing travelers to the second switch and carrying switched conductor back to fixture from second switch.
Both switches had cracked casings so I replaced them both without paying attention to how they had initially been wired, but afterwards got to thinking about it:
How is it possible to wire a switch so that it will not turn off a light? I can't come up with an answer, can you?
I appreciate your help, but you misunderstood my question: After I replaced the switches, everything worked properly, I was simply wondering how in the world the first yahoo managed to wire them so that the light couldn't be turned off from one of the switches.
Hot - traveler reversed on power side of the circuit.
So... while on the subject. Heres a good 3-way puzzler. How do you make a 2 single pole 120v switches on 2 different services in the same building act as a 3-way for 2 seperate sets of lights? I just did this the other day.
Mark Heller "Well - I oughta....." -Jackie Gleason