Whats the extra wire in my doorbell chime?

Old 11-23-18, 04:33 PM
Thread Starter
Join Date: Jan 2011
Location: US
Posts: 287
Received 0 Votes on 0 Posts
Whats the extra wire in my doorbell chime?

My house is 12 years old; I bought it 6 years ago.
There is one doorbell at the front door.
I took the cover off my door chime during a Nest doorbell install.
There are two cables going into it, each with two wires.

Both white wires are attached to center contact labeled transformer.
One red wire is connected to the left contact labeled front.
The other red wire isn't even stripped.

I disconnected the white wire that is with the unstripped red wire.
The door bell still lights up and rings properly.

1) Can I confidently proceed, ignoring the second cable (and leaving the second white wire unattached to anything)? Or do I have to do something with the 2nd white wire? (if so, what?)

2) I am guessing the second cable goes to the side door, but they decided not to use it. Is that likely right, or is there another likely explanation. Everything is drywalled, so there is nothing to look at.

Thanks much
Old 11-23-18, 04:45 PM
Norm201's Avatar
Join Date: Sep 2013
Location: United States
Posts: 10,000
Received 342 Votes on 308 Posts
That's correct. It's for a second or back door.
Old 11-23-18, 07:46 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 61,907
Received 1,483 Votes on 1,371 Posts
Interesting wiring. Just FYI..... those wires don't go directly to the buttons.
There is a splice at the transformer. Shouldn't affect your installation.

Thread Tools
Search this Thread
Ask a Question
Question Title:
Your question will be posted in: