TL;DR - a previously good switch is now unresponsive and showing voltage (High enough to be detected using voltage tester) on both the traveler and the neutral terminals even with nothing attached. Is my switch toast? Is my add-on switch toast by association?
I was repurposing a previously rock-solid GE/Jasco ZW3005 (12724) working as a 2way light switch to a different location as a 3-way switch along with a newly purchased add on switch. After a series of experiments I was fairly confident that my wiring topology matched the example that came with the add on switch and I wired accordingly, but when I juiced it up, there was darkness - no blue LED, no response to button pushes. This is when I poked around and found Load low, Line hot, Traveler and Neutral Hot
I shut off at the breaker and debugged tot he point where I isolated the source of the power to Neutral/Traveler connection to be within the dimmer switch (removing wires from traveler and neutral still shows voltage at the empty terminals). I didn’t have a multimeter handy and I’m not sure what the threshold of my voltage tester is for lighting up, so, I can’t be certain we see the full 120V at the terminals, but there’s something there…
Swapping in a 2-way (spst) switch where the dimmer was, using the black traveler line as a passthrough to the load and leaving the Red traveler empty (I think) confirms that my analysis of existing wiring was correct.
Anyone have any insight into what is toast, what is recoverable and what I messed up?