Simple switch problem

[Dougcole]

OK, I am stumped.

There are two ceiling lights in our forward cabin that both operate off of the same wall switch. There are also switches on the lights themselves.

The wall switch will not turn the lights off. In other words, there is power flowing to both lights even when the switch is in the off position.

So I pulled the switch from the wall, and found 3 wires going to two terminals, which makes perfect sense. i figured the switch had somehow shorted out. I got continuity between the terminals when the switch was in either position while all three wires were still attached. Bad switch, right?

So i pulled the wires and tested continuity again. Now the switch works perfectly.

I cleaned up the connections on the wires, figuring maybe they were somehow touching and put them back on the switch. Same as before...continuity in either position.

Changed the switch. Same result.

Ideas?

Here is a pic of the back of the switch.

 

[timjet]

Just a guess but are the 2 white wires supposed to be switched. They look like they're going to the same terminal.

 

[Nautoncall]

Just a guess but if one of the whites was connected to + through one light and the other was connected to ground through the other, then when you tie the 2 together in the switch, they complete the circuit.

 

[Dougcole]

I actually added the two white wires, because there was so little play in the original blue ones I couldn't reconnect it (I hate that). If you notice they are butt connected to two blues. I was careful to reassemble everything the same way as it was when I took it apart.

Oh, and I heat shrunk those butt connectors before I put the switch back in. I hate butt connectors, but there was no way around it here.

I don't think a ground wire would go through that switch. I assumed one wire coming in was from the + source and the other two each went to one of the light fixtures. Turning the switch off should break the connection to both lights.

 

[FF]

It was possibly set up as a switch in a house with a set of stairs is.

Can be switched off or on from either of 2 locations.

Other chance is it was to switch the lights from parallel to series operation.

Good efficient way to create a dim night light effect , before LED.

 

[Vyndance]

Is this a new problem? Has the switch ever turned off the lights?