Dimmer Switch

freddy001 · 12-03-2006, 07:19 AM

Ok, so I did not notice how my old dimmer was installed so have no idea what wires get conencted where ?, The olde dimmer had yellow, red. black and green wires. Please help

I have a chandalier connected by two light switches, The one upstairs is a three way switch (2 Blacks and 1 Red Wire). The box upstairs also has all white wires tied together. Downstairs where I want to install the Dimmer I have White, Black and Red Wire in the Box. My Dimmer has 2 Reds (One labelled or tagged Common/traveller) 1 Black and 1 Green. I know the Greens are ground, but how do I connect the dimmer so both switches work correctly. I hooked up One Red Tagged Common to the white wire, red to red and black to black. The dimmer does not work, as when I turn off upstairs light the dimmer downstairs does not work. i,e the dimmers do not operate independantly.

Please help

Square Eye · 12-03-2006, 01:12 PM

Do I understand you correctly that you have a dimmer upstairs and a dimmer down stairs?
If so, then your lights will never be any brighter than the dimmer that is set to the lower setting.
The easiest way to determine what wire goes where, is to get a meter. Set it on ac volts, over 100 volts.. Attach one end to ground, look for voltage on the other wires. When you find power, mark that wire. Then go flip the other switch. Back at the meter, look for power again.

IF you find power on a different wire, that is the other traveler. The remaining wire is the common.

IF the power is still on the same wire, then that is the common wire.

2 dimmers on one 3-way circuit is just not a good idea. You need to decide which end is most convenient to adjust the lighting from,
OR
Which end you will just want to turn the lights on from.. in a 'set and forget' dimmer situation, make that dimmer the least convenient to operate.

Either way, If you don't have a meter, a test light will also work.

Welcome to the forum!

JoeD · 12-03-2006, 03:39 PM

This will only take three tries to get it right. Connect any one of the three wires to the common wire from the dimmer. Connect the other two wires to the traveler wires from the dimmer. If it doesn't work properly swap one of the other wires to the common. If it still doesn't work swap the third wire to the common.
It is unusual to have one of the red wires as the common. Usually if there are two wires one color and a third wire another color the odd colored wire is the common.