How do I diagnose a wiring problem?

[BradScott]

I moved into a house with an existing security system that had only 8 zones. I replaced the security system with an Elk M1G and am successfully controlling the lights through UPB, and have some windows and all the doors working correctly. But, I have several windows that I can not get to show as closed. I can get to the contacts, and I have the wires homerun to the box, but I cannot get to the wires in between -- so I have no idea if they were run in series or how they are run. I've tried ohming wire pairs, and they always show open, but I haven't tried combinations of wires.

Any suggestions on how to diagnose short of trying every possible combination of wires?

 

[personalt]

I moved into a house with an existing security system that had only 8 zones. I replaced the security system with an Elk M1G and am successfully controlling the lights through UPB, and have some windows and all the doors working correctly. But, I have several windows that I can not get to show as closed. I can get to the contacts, and I have the wires homerun to the box, but I cannot get to the wires in between -- so I have no idea if they were run in series or how they are run. I've tried ohming wire pairs, and they always show open, but I haven't tried combinations of wires.

Any suggestions on how to diagnose short of trying every possible combination of wires?

Tone generator could be used to figure out what pair goes with what window.
http://www.youtube.com/watch?v=jP0AtN9hTP4

 

[BraveSirRobbin]

Are the pairs showing open even when all the windows/doors are closed? Are you sure the magnet is installed and making contact with the sensor? If not, perhaps tape a small magnet on the sensors and retest?

 

[Sandpiper]

I moved into a house with an existing security system that had only 8 zones. I replaced the security system with an Elk M1G and am successfully controlling the lights through UPB, and have some windows and all the doors working correctly. But, I have several windows that I can not get to show as closed. I can get to the contacts, and I have the wires homerun to the box, but I cannot get to the wires in between -- so I have no idea if they were run in series or how they are run. I've tried ohming wire pairs, and they always show open, but I haven't tried combinations of wires.

Any suggestions on how to diagnose short of trying every possible combination of wires?

The windows that are not working are probably wired in series. When I wire a house, I always run each window contact back to the panel and then put them in series, so that troubleshooting is easier. But not all installers do this, they may be wired in series in the "field". So for a series circuit, if one switch is bad, or one wire cut, then the entire set of windows do not work.

Here is what I would do.....for each window that is not working, remove the contact wires and put them together, bypassing the switch. This can be done by twisting them together or putting them on the same contact terminal. Then see if the zone circuit is continuous. If it is continuous, then you have a bad contact which you can now troubleshoot one at a time. If the zone circuit is not continuous, then you have a cut wire somewhere. The most likely place for a cut wire is not behind the drywall, but in the attic or crawlspace where someone pulled on a wire, or perhaps there is corrosion on a wire near a contact.

 

[Neurorad]

If you do what Sandpiper says - remove each contact sensor and short the connection by twisting them together, you'll be able to tell which cables feed each window, as well as figure out which ones are broken, if you do them 1 at a time, or grouped by room.

In my house, the windows in each room are wired together, in series. So, each room has a cable 'home-run' to the panel. When a zone covers more than 1 room, then the wires for each room are tied together in series at the panel. I think that is a very common way to wire for security.

 

[apostolakisl]

A combination of the two techniques may but what you need. The tone generator allows you to follow the wire in the wall behind the sheetrock and solve the problem quicker than any other technique. If you choose that route, you must get a high quality one or it will just not work for a damn and the good ones are a bit pricey. Manually closing the circuit at each contactor (romoving the contactor and twisting the wires together) is time consuming but free. Of course the time consumption will depend on what kind of contactor is installed, how difficult it is to pull, and how many of them there are. Also this technique only solves the problem if the problem is a bad contactor.

 

[pete_c]

In the last year looked at an older home in FL which had an alarm setup / doors and windows setup along with a newer home (neighbors which want to update alarm panels). I noticed that the older home alarm was most likely 3-4th gen alarm panel installed over the last 20 years. I am going to utilize a toner to backtrace what was done. I didn't see some of the logic used relating to the cables going into the panel and am guessing that some contacts are wired in series and buried in walls most likely near the contacts.

I didn't use an expansion module for the OPII installation in the home in FL but each door and window was wired with individual runs back to the panel about 10 years ago (with tear down and building of new home). Other than telling the GC I was into detail didn't oversee wiring as I had other concerns at the time of construction. I created zones at the panel connecting multiple window sensors. As the wiring was done pre completion of the home I had to utilize a toner for some of the wiring. I used a cheap toner and still have about 4 22/4 sets of wires to find in the walls and ceilings. The attic has blown insulation so even trying to find the wires in the attic is difficult. In the future plan on getting a better toner to continue to utilize the existing pre-wire.

 

[ChosunOne]

I moved into a house with an existing security system that had only 8 zones. I replaced the security system with an Elk M1G and am successfully controlling the lights through UPB, and have some windows and all the doors working correctly. But, I have several windows that I can not get to show as closed.

How many windows, and are they adjacent or scattered around? If they're adjacent, then can you make a reasonable guess which is nearest and which is farthest from the Control Panel, regarding likely wire runs?

I can get to the contacts, and I have the wires homerun to the box, but I cannot get to the wires in between -- so I have no idea if they were run in series or how they are run.

What kind of contacts, surface or recessed? Can you pull out all the wire where they are installed, or just the two wire ends connected to the contacts. If you can get to all the wire, what kind of wire is it: single pair, quad (4-conductor) cable, or what? Any colors involved, or all monotone? Even some of the _old_ twisted pairs had ribbing on the insulation and differentiated wire to help keep it straight.

Are the wires at the control in cables, or twisted or tied together in any form that suggests they are linked? Are there just pairs, no quad (4-conductor) cables?

I've tried ohming wire pairs, and they always show open, but I haven't tried combinations of wires.

Any suggestions on how to diagnose short of trying every possible combination of wires?

Trying every possible combo of wires doesn't take that long.
(1) Take all the wires in a bunch with enought insulation stripped off the ends so they all touch. Hold then so all the wire ends are touching. Call this Bunch "A".
(2)hold one meter lead in Bunch A so it touches the wires.
(3) Separate one wire, W1, from A and touch the other meter lead to it (meter set to Ohms).
(4a) If there is no continuity, you have eliminated that wire. Put it in Bunch "B", all wires without continuity.
(4b) If there is continuity, keep one lead pressed to W1, and divide Bunch A into approximately equal halves and test for Ohms again. Continue dividing the bunch until you find all wires connected to W1. Call this Bunch 1 ( or more probably Pair 1).

(5) repeat the process until you have all wires with continuity paired or bunched, or labeled as not continuous to anything.
The whole process will probably take less time than it took me to compose this. I don't compose very fast.

One more question: Do you still have the old panel, or do you know the brand and model? If it was late-model enough to have 8 zones, it probably used EOLR's. Did you find them? Did you locate any in the orphaned windows?

Okay, I lied. That was three questions.