Light Switch Problem


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Old 03-28-10, 05:47 PM
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Light Switch Problem

We have a light that is controlled by two separate switches on opposite sides of the room. Light switch A will turn on and off the light with no problems. Light switch B will turn off the light with no problems, but will only turn on the light if light switch A is in the on position?

Any suggestions?
 
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Old 03-28-10, 05:58 PM
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but will only turn on the light if light switch A is in the on
Both switches should be three way switches. Three way switches are not marked on/off. If the switch is marked on/off you have the wrong kind of switch.

Has it always done this or did it start after you replaced the switch? If you replaced a switch then you probably miswired it. The switch has an odd colored screw, the common. The other two screws are the travelers. Swap one of the travelers with the common. If that does't work keep swapping till you have tried each wire on the common with the remaining two on the travelers.

There is a more scientific way to do it but it is probably just as quick to swap wires.
 
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Old 03-28-10, 06:06 PM
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Nothing has changed over the last 7 years. All of a sudden it just started doing this nothing new has been installed or anything at all.

I understand what you are saying about on/off positions with a three way switches. However what I should have said is that when switch A is what we would actually consider the normal "off" position of a normal light switch...switch B will not work to turn the light on.

The switches have worked perfectly fine for about 7 years since installing and now all of a sudden this problem started without anything done to the switches?
 
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Old 03-28-10, 06:18 PM
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Flip a coin and replace one of the switches being careful to rewire not by the position of the wires on the old switch but by matching the wire that was on the odd colored, common screw to common on the new switch. If that doesn't work replace the other switch.
 
 

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