three black wires?

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Old 10-24-16, 10:01 AM
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three black wires?

I have a light switch that is the only switch to control the two lights at the sides of the garage door. I want to replace it with a timer switch that has two wires (instructions say black to black, then "other color" to blue). i removed the existing switch only to find out it has three black wires and nothing else. one single wire pushed into the back at the top. then a single wire looped at the bottom (making it two wires, one coming in, one going out). can anyone explain how i can wire this?Name:  20161024_112746.jpg
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Old 10-24-16, 10:04 AM
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Does each light get one of the hots? In other words, one incoming, two outgoing?
 
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Old 10-24-16, 10:14 AM
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i do not know. i assume they are wired in a series because they only operate together. i took off the other switches. black wire coming into my garage lights switch is coming from its own bundle of white/black/ground. oddly, the whites of all wire bundled are all wire nutted together and not going to any switches). the bottom wire goes to a wire nut joining another black wire, then to the next switch (porch lights), then that black wire goes to a different bundle of black/white/ground wires. third switch is not joined.Name:  20161024_122807.jpg
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Last edited by Sandy Ryczak; 10-24-16 at 10:52 AM.
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Old 10-24-16, 10:41 AM
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Figure out which is the incoming hot and then see what happens when you disconnect the other wires individually.
 
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Old 10-24-16, 10:53 AM
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this is a photo showing the white wires all joined together.
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Old 10-24-16, 02:11 PM
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is it possible for both wires to test hot? that is what I am seeing with my tester.
 
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Old 10-24-16, 02:44 PM
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What 'both' wires - you had three. What kind of tester?
 
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Old 10-24-16, 03:17 PM
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it is hard to put into words. the bottom wire is one wire, bent into a U, bare under the screw head. it come to the switch then leaves, so it makes two wire ends, but is the same wire. then i have the top wire that is pushed into the back. i tested them with a circuit tester touching one end to the bare part of the wire and the other to a ground. the three wires are visible in my first photo.
 
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Old 10-24-16, 03:26 PM
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OK, I get it now - you have two wires but someone got lazy and just stripped some of the insulation off the incoming hot and ran it through the screw to power the switch.
 
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Old 10-24-16, 03:39 PM
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that (those) wire is hot, but so is the wire on the top. is that possible? i am familiar with white (neutral) and black (hot). i want to put the timer switch in, but this is beyond my scope of knowledge.
 
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Old 10-24-16, 03:45 PM
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Is this a non-contact circuit tester? If so, wrong tool for the job. If not, tell me more about how you measured it to be hot.
 
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Old 10-24-16, 04:34 PM
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The two black wires on the same screw terminal are the hot wires. You'll need remove them from the switch.... cut and twist them together and connect the black of the timer to them.

The single wire on the switch is the light/load and goes to the blue wire.
 
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Old 10-25-16, 04:52 PM
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thank you very much, pjmax!
 
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