Sunday, August 7, 2011

Three way light switches... wtf...

OK so I have this weird electrical issue with the lights in the garage, yes there are a couple of other weird electrical issues, but for now I am going to deal with the lights in the garage. Basically the problem is that there is one light switch at the front of the garage that turns on the light in the garage, and the light in the storage room.

Sounds like no big deal right? Except that its the only light around, so you have to walk to the front of a tool/garbage ridden garage to turn the light on and off.... bit of a pita... so I decide to take a look at it, surely I am not the first one to think this sucks. At the door to the garage (the one that leads to the house) I have a plug, in the ideal place for a switch... so I take the plug out and low and behold there is a 3 way Romex in the box.

OK, so whats a three way Romex? Its an electrical wire that has white, black, and red. The red bit is the important part I'll get to that in a minute. Anyways the electrical plug (which was installed by my electrician) has one black, both whites connected to it, and the red is tied to a black heading back into the wall.

Now, I know 3 ways like I know italian. That is to say, not at all. But I know from the internet that there should be one "normal" wire coming from the panel, one "three way wire" going between the switches, and one "normal" wire going to the light.

Problem is that I have one normal wire going to the switch, and a three way at the front of the garage. At the back of the garage I have a plug, and a three way wire...

At this point my wifes unshakeable faith in me is getting shaken. She wanted the project house, but water is the bane of both of our existences, and whenever that stupid pump starts leaking she basically loses it. She wants me to call the electrician... I of course think, he didn't do it right the first time, what makes you think he will do it right this time...

You tube to the rescue, theres quite a few good links if you google for "How does a three way switch work". One of them actually lead me in the right direction (after I blue a fuse, and caused the stupid AC pump to leak again.. hate that damn pump, seems like if you turn off any breaker anywhere in the house the things stops working...).

The key is, there shouldn't be a plug there... after scratching my head and staring at some live electrical wires for awhile I decide to take a current checker and check the plug. Deader than a door nail...

Current checker? You see Holmes on Homes using it all the time, its this little pencil like thing that beeps when it comes into contact with current, the higher the current the more emphatic the beeping... Anyways since the plug is dead that means that the two wires in the box are connected to the other switch, and the light.

Finally all the wiring diagrams that I have been looking at make sense. I take the two three way switches I bought (oh yes, I planned ahead, you can't use regular switches they have to be three way) and I wire em up per the diagram.

From the fuse box (which is the only wire that makes the current checker beep when all of them are floating around in the air) you attached the black wire to the black terminal on the switch. The white wires get bound together and the black and red from the three way go on the other two terminals of the switch.

Next you go over to the other switch, again the two whites go together, but now the black from the "normal" wire that is going to the light goes to the black one, and again the black and red go to the other two terminals. It doesn't REALLY matter which one you put the red on, but I tried to stay consistent... Now with two switches floating in the air I decided to see if the light would turn on... sure enough it did, and turned off, and on regardless of which switch you used! Success!

Now I have a box that has a place for a plug, but no plug.... I will run another wire later, but for now I hooked the neutrals together, and spliced a wire onto the common terminal (black one) of the second switch. For those of you wondering, if you turn off that first switch near the garage, the plug doesn't work anymore, but its good enough for now.

1 comment:

  1. Bravo! I always have to read the instructions on those three-ways. Sounds like that would be a good spot for a motion-sensing switch..... :)