Hello. I'm trying to help a friend with this. At some point, he said both switches were working to control a ceiling light fixture then seemingly both stopped working around the same time. And bulbs were new. I used my Southpaw tester and found that regardless of each switch's position, I'm getting no power at the ceiling fixture. I also tested each switch and it seems neither outlet box is receiving power. All breakers are on and not tripped. I'm attaching some pictures. Thanks in advance for any help with next steps to troubleshoot.
Help troubleshooting 3-way switch wiring
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If there is no power at the switches then the problem is elsewhere. Try to find the box feeding the switches.
If it is a back stab push in connection like at the switches move the wires to the screws. Back stabs are a very common cause of this power loss.
If it is a back stab push in connection like at the switches move the wires to the screws. Back stabs are a very common cause of this power loss.
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If you decide to replace the switches, be sure to identify the wire connected to the black (may be brass colored) screw which is the common screw, before taking it loose. Losing track of that can cause lots of confusion, since switch screw configuration is often different on different makes of 3-way switches.
Are you sure we're looking at switches from the same 3-way circuit? The 2nd picture (1st 3-way) shows a /3 cable with red and black as the travelers (note they are on brass screws).
The 3rd picture shows clearly not that same /3 cable. It shows a /2 cable, with black and white as travelers (i.e. all the wires in the cable, which ain't right)... and a black from another /2 as the common, with its white unused. *You can't do that*.
I don't know how it ever did work, but it it a serious hack job, a real hillbilly wiring fiasco.
I can only imagine there is some intermediate point, a *fourth* box, where someone did something really weird.
The 3rd picture shows clearly not that same /3 cable. It shows a /2 cable, with black and white as travelers (i.e. all the wires in the cable, which ain't right)... and a black from another /2 as the common, with its white unused. *You can't do that*.
I don't know how it ever did work, but it it a serious hack job, a real hillbilly wiring fiasco.
I can only imagine there is some intermediate point, a *fourth* box, where someone did something really weird.
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When you do a retro install of a 3-way switching configuration, you can be driven to extreme measures to make it work. I can't explain why the 3-cond. would run to the one switch box and not the other but obviously there is another j-box somewhere that contains the magic innovation that switched the red and black travelers over to black white cable and used a black from another 2 cond. cable for the common connection. It's the old ho-made improvised 3-cond. wire that thankfully we never see so often. lol Might have been the original install and the electrician ran out of 3-cond. cable and decided to wing it.
That aside, if there is no power in either switch box on ANY wire, it will be necessary to find that magic j-box and see what has gone awry. I can't discount the possibility that someone drilled a hole in the wall and cut the feed wire in half but normally that would have tipped itself off by tripping a breaker. I'd make dead certain that all branch circuit breakers were delivering power at the panel and that all wires were secured to the breakers and neutral terminals. With that done, I'd go looking for that infamous j-box that will be the last hope.
That aside, if there is no power in either switch box on ANY wire, it will be necessary to find that magic j-box and see what has gone awry. I can't discount the possibility that someone drilled a hole in the wall and cut the feed wire in half but normally that would have tipped itself off by tripping a breaker. I'd make dead certain that all branch circuit breakers were delivering power at the panel and that all wires were secured to the breakers and neutral terminals. With that done, I'd go looking for that infamous j-box that will be the last hope.
Thanks for all the advice. It’s not the back stab connections on the switches as I was able to make contact with each wire directly with the tips of my tester. It seems the most likely scenario is a 4th junction box somewhere in-line that’s split off the black/red traveler from the 3-cond at the downstairs switch to the 2-cond black/white wiring at the upstairs switch and ceiling box.
Would the next best step be to check the circuit breaker hot and neural connections by removing the circuit panel? Or check for a faulty breaker? Not sure how I'd trace the wiring through the walls and ceiling back to locate a 4th J-box or even back to the circuit panel and specific breaker as I don't believe there's ceiling crawl space or attic access in that upstairs area.
Would the next best step be to check the circuit breaker hot and neural connections by removing the circuit panel? Or check for a faulty breaker? Not sure how I'd trace the wiring through the walls and ceiling back to locate a 4th J-box or even back to the circuit panel and specific breaker as I don't believe there's ceiling crawl space or attic access in that upstairs area.
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