What does it mean when the light on my garage door sensor is flickering?

When the light on your garage door sensor is flickering, it generally means the sensor is on the edge of losing its signal and is not in a stable, healthy state. If the green light on the receiving sensor is flickering or blinking, it means the sensor is receiving the infrared beam intermittently, not solidly. This is almost always due to slight misalignment, vibration, or a partially blocked beam. Even a tiny amount of movement can cause flicker, and you will notice the garage door may start to close and then reverse. The bracket might be loose, the track might be shaking when the door moves, or direct sunlight may be intermittently hitting the lens. If the yellow or red light on the sending sensor is flickering, it indicates an unstable power supply, such as a loose wire at the motor head, a partially broken wire, or a failing logic board that is not delivering steady low-voltage power. In both cases, cleaning the lens with a soft cloth, tightening all wire connections, and carefully realigning the sensors until both lights are solid and steady will usually resolve the flicker. If flickering persists after alignment, the sensor may be internally failing.