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View Full Version : Electrical expert needed for 3-way situation



Jameel Abraham
01-08-2008, 8:55 PM
I went to swap out a 3-way rheostat for a nicer one today and ended up spending 4 hours on it!!

Now usually I'm pretty good with three-way switched. Connect the commons, and the travellers are a snap.

But for some reason, all three rheostats I tried failed to switch the light back on when the other leg was switched the other direction. I re-wired each side twice and still the same, then re-wired a standard three-way (non rheostat) switch and it worked fine.

I've never had problems with three-way dimmers before. Is it possible that I shorted something out? I would think that the switch wouldnt work at all then, but all of them turned on and off and dimmed just fine as long as the other switch was in the correct position.

I'm pulling my hair out right now!

Mark Rios
01-08-2008, 10:24 PM
In the unit that I live in right now (I have three units on one lot and I rent the other two) I spent a couple of hours when I was rehabbing the whole place trying to figure out the same problem but with regular three-way switches. The configuration was...Power to a switch, light between the switches. Simple right? No big deal.

I kept telling myself, "I've done this how many times in my life? Why won't this stinkin' razzlemadingdangfrazzle thing work!!!"

So, after rewiring and rewiring and rewiring the switches, checking continuity in all of the conductors (seems like) fifty times, no nails or staples through the wires, turns out that one of the brand new switches was bad. Grrrrrrr!!!...Oh well, it happens.

Rob Russell
01-09-2008, 6:59 AM
If you have 3 switches controlling the same device/light, one of them has to be a 4-way switch.

Jameel Abraham
01-09-2008, 8:34 AM
In the unit that I live in right now (I have three units on one lot and I rent the other two) I spent a couple of hours when I was rehabbing the whole place trying to figure out the same problem but with regular three-way switches. The configuration was...Power to a switch, light between the switches. Simple right? No big deal.

I kept telling myself, "I've done this how many times in my life? Why won't this stinkin' razzlemadingdangfrazzle thing work!!!"

So, after rewiring and rewiring and rewiring the switches, checking continuity in all of the conductors (seems like) fifty times, no nails or staples through the wires, turns out that one of the brand new switches was bad. Grrrrrrr!!!...Oh well, it happens.

Yeah!! Exactly what I'm talking about. I think all my switches are bad. Probably doesn't help that while doing this I forgot to flip the breaker, I touched a hot to a hot and flash crackle the switch quit working. :o But I think that must be it. After I quit stewing about my lost time and effort, I'm going to try some new switches.


If you have 3 switches controlling the same device/light, one of them has to be a 4-way switch.

Sorry Bob, I wasn't clear. When I said " rheostats" I meant I tried three different ones at one end of a three-way situation, not all three at once (4-way). I've done that too, and 4-way switches wired into two wall sconces and every bottom outlet in a room is something that I will NEVER figure out. What kind of electrician would do that??!!

Cliff Rohrabacher
01-09-2008, 9:55 AM
I have installed several of the Lutron brand dual pole dimmers with memory. They go bad instantly if you wire 'em up wrong and hit 'em with power. Once you kill it it's well and truly dead. However, I don't know of a way to tell whether it's dead unless you run it with power -while it's wired correctly.

Chris Padilla
01-09-2008, 10:31 AM
Zeroth, TURN THE BLOODY POWER OFF!!! :D

First, you must make sure your switches are good. Looks like you are on your way for that.

Second, you must determine what wire is what and where the power is coming in. Continuity checker on a voltmeter or DVM can help here.

Third, when all else fails, lay the switches out in front of you and wired them up laying on the floor or something to figure out what is going on. You'll want to mimic what you *think* is in the wall.

Fourth, be patient, take a break...think clearly!

Good Luck!

Terry Kelly
01-09-2008, 7:05 PM
In some places it is required by code to have switched receps for room lighting so ya split the tab on the hot side so you can have one hot all the time and the other side off the switch leg for the light. A real common practice.

Ron Schmitt
01-12-2008, 8:30 AM
Zeroth, TURN THE BLOODY POWER OFF!!! :D

I work for an electrical wholesaler, and have sold Lutron for a LOT of years, if you hook up a dimmer with the power on, you will fry it instantly.

Jameel Abraham
01-12-2008, 9:11 AM
I have installed several of the Lutron brand dual pole dimmers with memory. They go bad instantly if you wire 'em up wrong and hit 'em with power. Once you kill it it's well and truly dead. However, I don't know of a way to tell whether it's dead unless you run it with power -while it's wired correctly.


I work for an electrical wholesaler, and have sold Lutron for a LOT of years, if you hook up a dimmer with the power on, you will fry it instantly.

Yeah, I did that, stupidly. So I think I fried three of them actually. Sheesh. Getting expensive now....