Ah yes, the three way switch. I did a routine swap out of two switches in the hallway upstairs and wouldn’t you know it one switch ended up controlling the primary on/off and the second switch would only turn the light on if the first one was in the on position.
First, some background. Three-way switches enable you to turn on or off a light from two different locations. When you look at a three way switch it has – lo and behold – three connectors, not the usual two.
Of course, make sure you have the power off before you even think about doing this stuff.
When you wire two three way switches you’re really wiring one big switch, typically separated by several feet. A big tip is that two out of three wires are used simply to connect one switch to the other. The last wire is used for incoming power or outgoing power.
My mistake was looking at the switch, not the diagram that came with it. Two of the three connectors were gold, one was black. i assumed that the black connector was the hot wire and the two gold connectors were for connecting the switch to the other switch.
In fact, as noted in the diagram on the switch package, the hot wire is down by the ground connector and it is colored gold like one of the connector wire threads. Confusing! Lesson learned on making sure the switch diagram makes as much sense as the connector colors.
There’s no shortage of web-advice on the topic – just turn the power off first!
I solved my wiring nightmare with Insteon switches. Fully programmable and can be computer controlled, but they work fine as 3-way switches that dim! www.smarthome.com
Posted by: David | February 24, 2009 at 12:10 AM