vseven
December 29, 2017, 4:29am
3
Do a search, there are multiple threads regarding 3-way installs.
With that said I just did a 4-way yesterday and have done multiple 3-way setups in the past. Personally I pull off all the switches, turn on the power, and figure out which is my line (hot) which should be the only wire with 120v. I turn the power back off then using a spare piece of wire to make a loop between the boxes (continuity) I figure out which wires are going from switch to switch and label them. Once that’s done the only wire left unlabeled will be the load (light) and I install the new switches using my now labeled wires.
I would guess that one of those two black wires that arn’t hot is to the light and the other is actually a traveler, maybe spliced somewhere else? Either way see above link or the big GE 3-way thread.