I'm absolutely confused. I'm trying to replace a switch. Switch has 3 screw terminals. Hot, Load and Ground.

Ground is correct. If hot and load aren't on the right screw terminals the switch won't work. Other wires aren't easy to tell which are which but I tried one way and it didn't work.

I checked with my multimeter measuring voltage between one screw terminal and ground and found which side had voltage. So I reversed the hot and load wires on the screw terminals. Still nothing and even though I switched wires the when I measured voltage with my meter it was still the same screw that read the voltage even though it had a different wire on it!?!?!?!

I redid the wiring twice on each side just to make sure.

Older home built around the 50's. No neutral wire at the switch box. Any body have any clue what's going on?

The switch requires a proper ground to work and that might be the problem but I'm still confused. I used a grounding pigtail temporarily to test the switch connected to the back of the box. 2 conductor armored cable goes to the box. Old cloth wrapped type wires. Disconnected switch and checked voltage between each wire to ground. Got about 70V for one and about 40V for the other.

  • What is this switch controlling, and can you post photos of the inside of the box the switch loop is fed from? Nov 16, 2016 at 23:39
  • @ThreePhaseEel Switch controls a light fixture. Can't post pics right now. I'm going to make an edit with some more info. Nov 16, 2016 at 23:50
  • I take it you're putting in some sort of "smart switch?" If so, what's the make and model on the unit? Nov 17, 2016 at 0:53
  • @threephaseeel leviton decorations dimmer timer. What's going on with the voltages I'm seeing at the bare wires? It doesn't seem right to me Nov 17, 2016 at 1:00
  • One of them should be reading an indeterminate voltage due to capacitive coupling -- however, the hot should be a solid 120V to ground. Maybe the BX armor is failing (i.e. the ground path isn't good any longer)? Nov 17, 2016 at 1:11


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