Garage Door Sensors

How my garage door sensors are installed. (4/19/2002)

Ryan Erickson
(Click to enlarge pictures)

Here's a few quick tips for anyone who would like to install magnetic sensors on their garage door. You may ask: Why install garage door sensors? Actually, you probably wouldn't ask, since if you're here, you probably already know!

My sensors currently:

  • Turn on the outside carriage lights if after dark.
  • Turn on a path of lighting inside the house if after dark.
  • Log the door open / close to the database.
  • Send a 'Door 1 Open / Door 2 Closed' type message to computers in the house, which is handy to know if someone is coming or going.
  • Blink the front house lights twice if both doors close. You can't see the doors from the front of the house, so if you're driving away, you can check the lights to ensure the doors are both closed.

    Someday I would also like them to:

  • Sound a chime over the audio system (different per door), if daytime, in non-nap rooms.

    The sensors I used are Sentrol 1045T screw terminal sensors (Wide Gap). They have a 3" make / break gap, so they work well on Garage Doors, and shouldn't get set off if the doors rattle a little in the wind.

    They are available at security sales stores, such as ADI ( They are also available at on-line places, such as and I'm sure others, but I don't know which ones. They are a bit pricey ($6-8 each), but they work extremely well.

    In our previous house, I installed the sensor above the garage door, with the magnet attached to the top of the door. It worked fine, but was a royal pain to install and adjust so that the magnet on the door didn't hit the sensor as the door went up and swung out of the way. In the new house, I found what I consider a better place for the sensor -- right behind the track of the door. In their current location, they're nearly invisible.

    It's hard to explain, so I took some pictures...

  • IMG_1640_mid.jpg
    (Click to Enlarge)
    This is a picture of the two garage door sensors installed, one in each door. In this shot, you can only really see the wires, the sensor on the left door, and the magnet on the door on the right.

    In our installation, the wires go to our Home Automation controller, in the basement. Where you attach yours is up to you. I can't help you with a Powerflash, because I've never used one.

    (Click to Enlarge)
    In this shot, you can see both the magnet attached to the door, and the sensor it lines up with. The sensor is barely visible to the left of the magnet, hidden behind the track.
    (Click to Enlarge)
    In my case, installing the sensor was easy. The door installers put in a finger shield, which runs behind the track, attaching to both the track and the wall. I just chose a hole in the finger shield, ran the wire through it, attached the wire to the sensor, and screwed the sensor into the finger shield.
    (Click to Enlarge)
    In this shot, you can see the magnet, and the mark on the garage door at the top of the magnet that I made to tell me where to install the magnet (it's just a scratch in the metal -- you may need to enlarge to see it). If the magnet is installed to the back of the door as far as possible, it just lines up with the sensor behind the track.

    After marking the spot, I opened the door, and it was easy to attach the magnet with two long sheet metal screws.

    (Click to Enlarge)
    I've had it installed since moving into the house, at the end of June 2001. I have had no problems or false triggers. One of these days, I need to get out there and attach the wires to the wall, and maybe put a grommet or something on the wire where it goes through the finger shield, so it won't be damaged by vibration.

    Copyright Ryan Erickson <> 2002.
    Redistribution of this document as a whole or any of the pictures individually is permitted in any medium provided this copyright notice is preserved.

    Last update 19.04.2002.