Help! Didn't label my doorbell wires! O_o


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Old 08-07-16, 11:30 AM
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Help! Didn't label my doorbell wires! O_o

I did a bad thing. I removed my old doorbell without labeling the wires. My new doorbell has 3 terminals (Front, Trans & Rear). There are 3 main wires coming out of the wall. Each main wire splits off into 2 smaller wires (1 red / 1 white). So thatís 6 wires in total. I have both a front and back door button to hookup. Please help! 16 cool points will be awarded to the first helpful answer!
 
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Old 08-07-16, 12:41 PM
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Good time to buy a cheap multimeter if you don't have one. Use the multimeter to find the cable that has 24 volts AC on the red and white wires. That's your transformer. The other two will be front and rear. You can guess and check or you can use the multimeter to identify which is which, by measuring the resistance between the red and white wire (don't do this on transformer pair). It will be very low when the button is pushed and very high when it isn't.

If you don't want to buy a multimeter, connect one cable to the transformer terminals and use a little piece of wire to short the front terminals. If the doorbell rings you've hooked up the right cable to transformer. If it doesn't, try another cable until you find the transformer cable.

Good luck!
 
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Old 08-07-16, 12:51 PM
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Take one cable at a time and connect it to transformer and front. When the doorbell ring....you've found the transformer cable.

Leave one of the transformer wires connected. Take the remaining transformer wire and connect it to one each of the other cables. Now take the remaining two wires from the two cables and connect them to the F and R.

Try the doorbell. If it's backwards... swap the F and R wires.
 
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Old 08-07-16, 02:27 PM
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The method that PJ describes is how I would do it.
 
 

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