Electrical – How to install a dimmer switch

electricalswitch

A friend was trying to help me install new dimmer switches and instead of disconnecting one wire and putting it on the new switch, he just cut the wires and couldn't figure out how to put them back.

I used my multimeter to find which wire was which and got the three way switch to work, however next to my three way switch I also have a single pole switch for the lights above my sink. Now, that switch alternates with the three way switch. One set of lights goes on, and the other goes off. If the switch by the garage is off the lights above the sink won't work. I think I have the traveler wires reverse??

Best Answer

Typically A dimmer that can be used in a three way circuit will have a common (black) wire, and two (non-black, non-white, non-green) travelers. Here is a wiring diagram from the installation instructions of a random dimmer.

Random wiring diagram
It can also be installed as the second switch in the circuit.
enter image description here

As you can see, in this example the common wire is black, while the travelers are red. Without further detail about your current wiring, it's impossible to provide more assistance.