Making a Simple Garage Door Monitor By Yourself

Electronic garage door openers with remote controls have made it easier for busy Americans to enter and exit their homes, but it is also unfortunately easy to open the door by accident or to leave the door open.

A garage door monitor can alert you to an open door and help you remember to close the door, thus preventing possible theft or home invasion. You can make a simple but fully functional garage door opener with inexpensive items that many people have around their homes.

Store Bought Kits
Many garage door monitor kits are available at hardware stores or DIY sites like These are reasonably inexpensive and easy to install. Usually the kits come with one sensor and one monitor. The sensor is mounted in the garage, according to manufacturer instructions. Often you will not even need any tools to mount the sensor - instead, you can use a self-adhesive material such as Velcro. The monitor is placed inside the house, wherever it is most convenient for you. The sensor and monitor communicate via radio waves, and when the door is open, the monitor will alert you with a light or a sound.

Your garage door monitor doesn't have to be store-bought, though. Only you will know what will work for you, but you are only limited by your creativity. For example, you could create a garage door monitor by carefully angling a mirror or a series of mirrors that allow you to see if the door is open by just opening the garage door. An extra remote control for your garage door opener could be mounted inside the house, and if the door is open, you could use that to close the door.

You could also attach a colorful scarf, hankerchief, or cloth rag to the inner top of your door. When the door is open, it will dangle conspicuously, and again you can use an extra remote control garage door opener to close the door. When the door is closed, it will hang out of the way and blend with the rest of your garage.

Scarf and Pulley
If your door is not set directly in front of your entrance into the garage from your house, though, you will not be able to see a scarf attached to the door. In these cases, you can use a couple of inexpensive pulleys, a length of string or twine, and the aforementioned scarf. By attaching the pulleys behind the garage door and attaching the string to the garage door, you can create a simple system where the string rotates when the door is up or down. With a little trial-and-error, you can find the spot on the string where you can hang the scarf that will alert you to the door's position.