Whether you have an obstruction, a leaf stuck to a sensor by a spider web or a faulty wire connection, you can correct simple garage door safety sensor problems yourself with a little DIY troubleshooting.  Does your garage door close just fine during certain times of the day, but does not at other times?  Did you have a new garage door opener installed? Is the house new construction and you just moved in? Did you close the garage door only to have it open again and the opener lights start flashing?  

What is going on?! You have probably experienced the biggest nuisance of a malfunctioning garage door.  The most likely culprit is the garage door opener safety sensor system.

Before you call a technician, check your garage door safety sensor system:

Garage door sensor and Mother Nature?

If your garage door doesn’t stay down, note the time of day.  Does it seem to happen during the same hours of the day and work fine during others?  Is the sun shining directly on the front of the garage door?  The pair of safety sensors are a system that sends a signal to detect something in the way of the door.  Full sunlight on the sending sensor, can wash out the beam to the other sensor.  Simply swap the sensors to the other side so that the receiving sensor is now in the shade and that should take care of it.   Swapping sensors doesn’t work?  Make some shades or move the sensors back from the opening to give some shade.

Garage door sensor obstructed or broken?

When sunshine isn’t the problem, see if something has fallen in between the sensors and obstructed the beam.  There is no obstruction? Wipe the lens of each sensor with a damp paper towel to remove spider webs, dust, paint or any debris that is preventing the sensors from functioning.   No obstructions and cleaning the lens didn’t work? Are the sensors in alignment?  Did the sensors get bumped?  Straighten the sensors out to get them realigned.  Usually there is one sensor that has a light on all the time.  Adjust the sensors so that the lights are illuminated on both sensors.  They should be aimed directly at each other.  The same distance from the floor and the same distance from the door is important. 

Do either of the sensors have an illuminated light? If not, there might be a faulty connection or broken wire.  Try wiggling the wires to see if a light will flicker on and off.  Still no light? Remove one wire nut or electrical tape at a time to see if a wire has broken or lost contact.  If the connections are good at the sensors and still no lights, check the location of the wires going into the motor.  If the connections are good at the motor, there is a chance that the wiring between the sensors and the motor have a break. 

Time to call a technician for safety:

A technician will determine if the sensors are broken, if local wires are bad or if the internal wiring is malfunctioning.  Broken sensors will be replaced using existing, functional wiring.  Replacement wiring will be installed across the ceiling to the wall and down each side of the opening bypassing the broken wire.   Saving money is always important, but be safe by calling a skilled technician anytime there is an electrical issue.