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I need help figuring out why my old wired doorbell doesn’t work. I currently have the button at the front door disconnected from the 2 wires.

When I test with a multimeter at the transformer, I’m getting 19.3 volts ac. When I go to the chime (an old Trine chime) and test, I also get 19.3v. I don’t seem to be getting anything at the front door itself (0v).

To complicate things, all the low voltage wires involved are red. So when I disconnected my chime, I’m not sure which is which now. If I’m understanding how typical set up works, one wire from the transformer goes to the chime and one goes to the button. But how am I also getting 19.3v at the chime when the front doorbell button isn’t even connected? And one wire I see at the front door is supposed to be from the transformer and one would be the return from the button to the chime?

In my case, when I connect one of the wires going into the chime on the “trans” screw and the other on the “front” screw it seems like the chime gets activated (one time it actually made the chime ding). I switched the wires around on the chime (since I’m not sure what wire is what) and it seemed like the chime got hot and was stuck in an activated/running state. Can anyone explain what may be going on?

In either case, nothing seems to be getting to the front door wires when I test. Please see attached photos. Thanks in advance.

chime

front doorbell

transformer

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The fact that all your wires are red does not matter too much as you have no rear door bell button to worry about.

Normally, power would start at the transformer, go to the TRANS connector on the chime via one red wire, from FRONT go to the front door via another red wire, and then come back from the button to the transformer via the third red wire. The button is normally open; you push the button, current flows through the button and the chime rings. If you hold the button closed, the chime will ring once and then sit there, humming and overheating until someone comes and forcefully takes your finger off the button.

So if the button is removed, but connecting the two red wires at the chime causes a muted ding, continued buzzing, and heat, that suggests that something similar to the button being pressed and held has happened. The most likely thing is that the two red wires that go to the button, one from the transformer and one from the FRONT screw on the chime, have somehow gotten connected to each other by something other than the button - if I was to guess, most likely I'd say they are held in place with staples, and one of the staples has now made contact with both wires. Possibly rodents have eaten the insulation, they seem to love doing that. Almost certainly you won't be able to find where this has happened, but you can follow the wires, if it's an older house, and look for it. (Newer houses seem to be constructed so as to hide all their inner workings. My son has just bought his first house, and had a truly annoying time trying to pull a network cable because of that.)

If you can find where bare copper from the two wires is touching, and fix that with (e.g.) electrical tape, you can then hook everything up again and have a working door chime. If you can find the full run of wire, you can simply leave the old stuff in place and pull new. Otherwise, I'd go with the suggestion of getting a wireless doorbell, and I'd also suggest that you change the battery in the doorbell button once a year, at the same time you do your smoke detectors.

Edit: If you want to follow and try to repair your existing wires, you need to follow the wire from the chime to the door; and almost certainly, the wire from the transformer to the door goes past the chime, but doesn't surface at the chime, so you can't immediately see it. Unscrew the chime from the wall, look through the hole the wires come out of, likely you'll see the third wire through that hole. You may also be able to see the direction the wires take after they go by the chime. If they go up, likely they are routed through your ceiling to the front door. If they go down, they may surface somewhere else in the basement and run towards the front door from there. But unless there is only attic above your ceiling, and you are confident about walking around up there, if the wires go into your ceiling it's unlikely you'll be able to find and repair them. If you are able and willing to go into that space, the wires are likely stapled to the joists - the beams that hold the ceiling up. It's at the staples where I'd expect to see wear and bare copper.

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  • I am planning on getting a ring battery doorbell if this doesn’t work out but was giving the wired option one last chance. Your theory sounds plausible. It’s an older house - I can see where the wires from the transformer in the basement go up towards the pantry on the middle level where the chime is. I can’t quite tell the path taken by the wires to get to the front door. Obviously I’m not looking to tear any walls out or anything and pulling a new wire I wouldn’t be confident in knowing how to do. What’s the best way to follow the old wiring (short of opening walls or something)? Thanks! Commented yesterday
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    If you see both wires go up to the pantry from the transformer, but they don't come down the same chase, you may be out of luck. In my previous house, the wires went up to the pantry from the transformer, then at the chime we could see that they continued upwards from there into the ceiling. In this house, the wire coming down from the chime continues across the basement to the front door. I've added some rudimentary old wiring following instructions in my answer. Commented yesterday
  • Thanks. Were you able to attach those instructions? I should say I can’t say for sure where the wires from the transformer are going exactly. I see the 2 wires coming from the floor in the pantry on the middle level going into the chime but beyond I can’t say for sure what the set up is Commented yesterday
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    I did - might have to refresh the page before you see them. Commented yesterday
  • After taking a closer look at the wiring near the transformer, it looks like one wire goes upstairs to the chime and there’s a wire that returns from the chime and pairs up with the other wire from the transformer & goes across the ceiling in my basement starting in the unfinished area and goes out towards the finished part and then out the front of the house & over to the front door trim and then behind the wood where the button is located. That makes more sense. But where the wiring got messed up idk - I’ll inspect where it’s exposed outdoors @ front of house to see if I see anything Commented yesterday
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  1. Old electromechanical chime timers require some device, such as a leaf switch, to pulse the solenoid that pulls the iron plunger to hit the chime bar. Otherwise, the solenoid coil would be continuously activated as long as the doorbell button was held, giving a single, muted "ding" and overheating the solenoid until it burns out.

    Check inside the metal box with three terminal screws for a leaf switch that interrupts the plunger; likely it's contacts are burned or welded together. Though that can be fixed, it is likely to fail again. Consider replacing with a modern chime, or an annunciator that plays MP3 files.

  2. Since you've disconnected the chime, you've likely opened the circuit to the doorbell button, so there's no voltage across it. Put either the chime coil, or a small 24V or 32V lamp, or some resistor between 100Ω and 1kΩ, to get the actual voltage at the doorbell.

    If the voltage is still near zero at the doorbell, likely there's a break in the wire inside the wall. If you cannot find and fix that break, it might be easier to install a wireless doorbell than to open the wall to access wires.

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  • If you find the question clear and good enough for you to answer, than give the OP Vote-Up as reward Commented yesterday
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I had exactly the same trouble as described. I found that I could test the chime/transformer by shorting across the "trans" and "front" or across the "trans" and "rear" (with the doorbell switch disconnected) and elicit a sound. Despite the previous answer, my model chime, and possibly yours, will allow the button pressing party to hold the button.

The same color wires aren't an important concern, as it's merely a pair of wires to the button at the door and has no polarity.

If shorting the trans and either front or rear gives you a chime, the wiring is suspect, or the button is suspect. You can check the wires by removing one from the transformer, then shorting the wires at the button. Touching the transformer wire that was removed should ring the bell if the wires are good. Otherwise, the wireless option as noted is viable.

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    thanks for the reply. what do you mean by shorting process? Sorry- I don’t know electrical much Commented yesterday
  • If you find the question clear and good enough for you to answer, than give the OP Vote-Up as reward Commented yesterday
  • In the context of my answer, the shorting process is the test involving connecting the trans and front contacts or the trans and rear contacts, with the wiring to the doorbell switch disconnected. Commented yesterday
  • I’m trying to understand..so currently I have the front doorbell disconnected. My idea was to reconnect the wires at the chime and then touch the wires at the front door together to see if the chime would ding but nothing happens (and it tests 0v). And when I connect the wires back to the chime (I’m not sure which wire is coming from where) it either dings the chime or it just makes a humming sound and gets hot (like it’s stuck in an “on” position). When I test at the front with the wires all connected at the transformer and chime, still nothing Commented yesterday
  • disconnect the wires at the transformer short across trans and front or short across trans and rear if you get a chime, the transformer is good, the chime is good if you don't get a chime, one or the other is not-good. Let's guess you get a chime... Disconnect the door bell button, connect the wires at the transformer. If you get a buzz, the wires are shorting inside the wall. If you don't get a buzz at the chime, touch together the two wires that extend from the house. If you don't get a chime, the wires are open. If you get a chime, the button is faulty. Commented 19 hours ago
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Occam's wiresnips say the wires to the front door are broken (and probably shorted) someplace. One wire goes from transformer to front door. One wire goes from transformer to "trans" (center) screw of chime. One wire goes from front door to "front" (topmost) screw on chime (unless you want the "single-bong" rear chime noise, rather than the "bing-bong" double chime noise of the front.) If you had a rear doorbell as well, there would also be wires from the transformer and chime to it.

With the front doorbell wires disconnected as shown, there should be no voltage at the chime wires. That you have voltage there with them disconnected and/or the doorbell not pressed indicates a short of the doorbell wires [edge case - a lighted doorbell, if connected to the wires when measuring, will show voltage at chime, but the light limits the current so the chime does not operate until the button is pushed.] If the front doorbell wires are twisted together or otherwise connected, then you should have voltage at the chime. So, unless you are going to jump on the battery-replacement-train of wireless doorbells as your solution, you apparently need to replace the wiring to the front door. You may find a little more access to the wires behind the chime unit if you dismount it from the wall.

If you use a long wire with your multimeter, you should be able to sort out which wire is which (and mark them) by disconnecting all the wires, then connecting the long wire to a wire to be tested, and looking for resistance (low) between that wire and other wire ends. There should only be one other wire end with non-infinite resistance when you do this test. If there are two or three other wires with low resistance, you have a short. If there are none, you have a break. The testing wire needs to reach from the front door to the chime and transformer locations, and between the chime and transformer locations (so long enough for whichever is longer of those.)

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  • Thanks for the reply. I have a multimeter. Unfortunately I disconnected the wires to the chime (which are both red) and lost track of which was connected to trans and which was connected to the front screw. My idea was to try connecting the chime again (trying one way and then reversing the wires since I don’t know which is which) then going to the front doorbell and touching the wires together but nothing happens - when I test at the front door with everything else connected I get 0v. There’s likely a break/short in the wiring to the front door? Commented yesterday
  • So, as per the last paragraph, use an additional wire and your multimeter to sort out which wire is which. You could also and more quickly (after disconnecting wires at the transformer) check resistance between the wires at the front door. With them all disconnected, that should be infinite resistance. It may not be. As per the first sentence, without being on-site to test, it seems very likely the wires to the front door are at least shorted. Broken is also possible. Commented yesterday

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