What does it mean when one garage door sensor is green and one is red?

What does it mean when one garage door sensor is green and one is red?

There usually is a light on each sensor. One will have a green light that signifies power to the units, and the other will have a red light that signifies that the sensors are `seeing' each other (i.e. that there are no obstructions). If the red light is blinking, the sensors are not aligned.

Does sunlight affect garage door sensors?

Garage door sensors use infrared light. … This is why a garage door might stop closing if strong sunlight is shining on the eye of a garage door sensor. So the answer to the question is yes. Sunlight can affect a garage door sensor.