Troubleshoot Garage Door Safety Sensors that Are Off or Flicker

Note: Any garage door opener or replacement logic board manufactured after 2022 will no longer have this feature.

Note: For troubleshooting safety sensors 041-0136, those having square LED lights and a bolt through the sensor, see article Features and Benefits of the 041-0136 Safety Sensors

The safety reversing sensors must be connected and aligned correctly before the garage door opener will move in the down direction. Temporarily until you determine the issue, the garage door can be closed by pressing and holding the Door Control push bar until down travel is completed.

When your garage door does not close and the garage door opener lights flash 10 times or the garage door sensors are not lighting up, there are a few simple steps to help you figure out the issue.

If the sending sensor is glowing steadily and the receiving sensor is off of flickering typically is a misaligned or obstructed sensor. You can determine if:

• The safety reversing sensors are obstructed or misaligned.
• A sensor is faulty.
• There is a short or broken wire for the safety reversing sensors.

When the Safety Reversing Sensors are Obstructed or Misaligned

1. Locate the safety reversing sensors on both sides of your garage door.
2. Make sure nothing is blocking the sensors. Once you’ve removed any obstructions, the LEDs in both sensors should glow steady.
3. Try closing the garage door with your remote control. If the door closes, great, you’re done!

If you’ve determined the sensors are not blocked and your door still won’t close, consider these options:

How to Align the Sensors

1. Loosen the wing nut on the green LED (receiving sensor).
2. Adjust the sensor until the green LED is glowing steady and tighten the wing nut.
3. If the green LED is still blinking, then perform the same procedure on the amber LED (sending sensor).
4. Use the remote control to close the garage door.

• If the door closes, test the safety reversal after this adjustment, and you’re done.
• If the door doesn’t close, check wiring connections.

How to Check the Wiring Connections

1. The white wires connect to white terminal.
2. The white/black wires connect to the black terminal.
3. Use the remote control to close the garage door.

NOTE: If your garage is pre-wired, the wire color may be different.

TIP: Gently tug the wires to make sure they are properly connected.

How to Check the Safety Reversing Sensors

1. Remove the sensors from the brackets.
2. Remove the wires from the wire nuts or cut the sensor wires 12" from the sensors.
3. Strip both ends of wires from each sensor and twist like colored wires together. Proceed with both sensors to the garage door opener motor unit. NOTE: This step is not necessary for safety sensors 041-0136
4. Remove existing wires from the white and grey terminals on the back of the operator.
5. Attach or insert white wires into the white terminal and black/white striped wires into the grey terminal.
6. Point the sensors at each other - if both sensor LED's turn on, there is an issue with your wiring. Replace the wires between the opener and the sensors. If the LED’s DO NOT turn on, replace the sensors.

How to Check for an Open or Shorted Wire

When the receiving sensor (green LED) has power the LED will glow steady. If the LED is not glowing steady, this means there is an open or shorted wire.

1. Replace the wire currently connected to the sending sensor.
2. If you have replaced the wiring and the sensor is still not glowing steady, replace the safety reversing sensors.
3. Use the remote control to close the garage door.
   • If the garage door closes, test the safety reversal after this adjustment, and you’re done
   • If the door doesn’t close, try switching the positions of the sensors

If you experience additional issues with safety reversing sensors, see Troubleshooting Safety Reversing Sensors When Both LEDs Off