I've been trying to install a Lutron Caseta smart switch, which definitely needs a neutral wire, in my older house. Despite following the wiring instructions I've used for similar switches, this one just isn't cooperating. When I turn the breaker back on, the light starts flickering, and the smart switch keeps rebooting like it's losing power. It works fine with a non-neutral dimmer, but I really want a standard switch here instead.
It seems like I might be dealing with a 3-way switch setup, as the power comes from the fixture. I opened up both junction boxes but the only place there are multiple Romex cables is in Junction Box A, where I'm working on the smart switch. Here's the wiring setup:
- Junction Box A: 2-wire (white/black) and 3-wire (white/black/red)
- Junction Box B: 3-wire (white/white/black)
- Light Fixture: 2-wire (white/black)
In Box A, I found a capped white and black wire, and a white wire connected to the black screw on the old switch. When I test it with my multimeter, only the white wire shows 120VAC to ground. I'm puzzled about why the white and black are reversed. Shouldn't the capped wires at the back be neutral?
And also, where's the red traveler wire going? The only red wire I see is in Box A. Plus, there's only one 2-wire cable at the fixture, which makes me wonder if there should be a 3-wire running between the fixture and Box B. Can anyone help me make sense of this?
2 Answers
It sounds like your issue might stem from where the neutral ends in your circuit, especially since you're using a smart switch. Typically, in a 3-way circuit, you'd have an additional traveler wire, sometimes the red one, switching the load between the two locations.
It could be that your neutral wire is, unfortunately, connected or routed incorrectly, perhaps behind the fixture. If you only have the single 2-wire Romex at the fixture, there might be some sneaky wiring mistakes going on. When doing this with older homes, it's really common to find wiring that isn’t up to standard. Just to clarify, when you check the wires, make sure you're not confusing your hot and neutral. If there’s voltage present where it should be neutral, that's definitely a red flag. Take your time with the multimeter to trace everything out!
You've raised some valid concerns about the wiring, and I can tell you that old homes often have obscure wiring setups that make it hard to figure out where neutrals or travelers are.
In your case, if the smart switch needs a neutral and it’s not available, that explains the flickering and reset you’re seeing. I would suspect that the neutral might not be reaching the smart switch properly. Definitely try installing the smart switch at a known good location or with a different, simpler fixture just to verify the switch itself works. Also, never connect a neutral to a ground unless you've confirmed it's safe; that can lead to other dangerous issues!
Good advice! I wouldn’t take chances with grounding and neutral; always better to trace everything out first. When troubleshooting smart switches, check if the switch is really compatible with your wiring setup as well. Good luck!
You're spot on with checking the voltage! I had a similar old house wiring issue before where the neutral was completely mixed up, leading to my switches malfunctioning. Just be careful while you troubleshoot; old wiring can be tricky, but you can definitely get to the bottom of it.