I have no issue troubleshooting 3-way switches but this is an odd one. At some point a handyman replaced switches and messed up a 3-way switch setup. However it's 2 lights and 2 switches:
– light A and switch A at top of stairs
– light B and switch B at bottom of stairs
I want both switches to control both lights simultaneously. However, the way it is now:
– switch A controls both lights fine
– switch B only turns on/off light A, has no effect on light B
Switch A has 3 regular leads: red end which is connected to one traveller terminal, white end which is connected to the other traveller terminal, black wire connected to the black screw but then continues to another switch for an outside light so this appears to be the hot. Then there is an additional end of another black wire. This extra black wire controls light B and seems to be the key to the problem. If I touch it to the hot wire, then light B turns on as expected, if I attach it to either traveller screw, then light B turns on and off with switch A. I'm just not sure what I can do to make light B also turn on and off with switch B.
I've most combinations and nothing seems to get both lights working with both switches. Maybe I'm missing a white wire to light B in the mix somehow?
Thanks for any troubleshooting tips you may be able to provide.
Best Answer
I figured it out, once I had both switches out of the box and pulled out all the bundled wires it was easy enough to figure out where everything was going and what was going on based on what was working, there was a hot circuit coming in, circuits going out to each light, and the 3-way circuit going between the switches, so it was easy enough to identify the lines running to each light and put them in parallel. Cheers.