Garage door opener sensors are a safety feature that prevents the door from closing if something or someone is in the path of the door. The safety sensors use an invisible beam of infrared light to detect obstructions in the garage door’s path. The sensors won’t allow the door to close with their infrared beam blocked.
At times, the sensors can be knocked or jostled out of alignment. When that happens, the garage door opener won’t close the door and an error code will blink on the motor unit. On many garage door openers, the lights on the motor unit will blink 10 times when the sensors are blocked or out of alignment.
When the door won’t close and the opener lights blink, check for an item or person blocking the safety sensor beams.
Rays of sunlight can trick the garage door sensors into thinking there’s something in the door’s path, preventing the door from closing. Sun shields are an inexpensive solution. If the opener closes the door at night but not during the day, install sun shields over the safety sensors to eliminate sunlight interference.
If there’s nothing blocking the eye sensors and sunlight isn’t causing the problem, check their alignment. You may have bumped a sensor out of position.
How to Align the Safety Sensors
Each safety sensor has an indicator light. The sending sensor, which has the yellow light, transmits the infrared beam to the receiving sensor, which has a green light.
The yellow sending sensor light should always be lit. You’ll see the receiving sensor’s green light lit when the sensors are aligned and unobstructed.
Make sure that the yellow light is on and then check the green light on the receiving sensor. If the green light is off, realign the garage door sensors so the green light turns on then try closing the door.
How to Test Garage Door Opener Safety Sensors
If the above troubleshooting tips didn’t help you resolve the safety sensor problem, test the safety sensors directly at the motor unit using short strands of sensor wire.
This test will help you determine whether you have defective sensors or a wiring break that you didn’t see when visually inspecting the wires.
Check the sending sensor first. Follow these steps to connect the sending sensor directly to the motor unit using short strands of wire:
- Remove the sending safety sensor with the yellow light from its door rail bracket.
- Disconnect or cut the sensor wire about 1 foot from the sensor end.
- The sensor wire has 2 strands. Separate the strands and strip 1/2-inch of insulation from the end of each strand.
- Take the sending sensor to the motor unit.
- Disconnect the existing safety sensor wires from the motor unit.
- Connect the short, white sending safety sensor wire strand to the white motor unit terminal. Connect the other sending safety sensor wire strand to the gray terminal.
- Check the yellow light on the sending safety sensor.
If the yellow light doesn’t turn on, replace the safety sensors because they are defective. Here’s a video that shows you how:
If these troubleshooting tips don’t help you get your garage door opener working again, continue with DIY steps described in our Why Won’t My Garage Door Opener Close the Garage Door? article. You can also have Sears Home Services fix your garage door opener. Our repair experts can quickly fix the problem with your garage door opener, no matter where you bought it.
Sears is committed to helping you manage your home – wherever and however you need us. Trust us to help you fix your garage door opener and any other problems in your home.