Replaced 3way switch only one works

[pauls340]

I replaced a 3way switch with a new rocker switch style. The two black wires go on one side, the two whites are together, the red goes on the other side of the switch. The upstairs switch only works when the downstairs switch is in the up position. Does it matter which of the two blacks are attached on the lower screw of the switch?

 

[41ratrod]

YES it does you can google it and see wiring diagrams on this.

 

[darcyh]

Hello:

You've mixed up the wires.

At my daughters house I noticed the same thing. She tolerated this for months, did not know any different. The previous owners installed decora switches and probably mixed up the wires.

Here's how i solved the problem:

- as there was only 3 wires in the box it was time to play with alligator clips
- this trick took three people including me. One on the breaker in the basement, one at top of stairs and me on main floor
- used alligator clips to try different combinations at the switch
- daughter in basement would shut off power, I'd change the wires, person at top of stairs would test the upstairs switch
- finally got the right combination after third try

MAKE SURE YOU SHUT OFF POWER BEFORE TRYING THIS!

Once we were done, daughter was very pleased with outcome! And, I had a beer.

Regards,

Dave

 

[Falcon67]

The red and black is usually the traveler, so the Decora switch may have the traveler terminals in the different place than the regular switch.

 

[pauls340]

yeeup, Decora switch is different from older 3way. Flipped the two blacks and everything works like designed. Thanks all.