A blinking sensor LED means the receiver is not getting a clean beam. A steady light means it is. On most units the sending eye shows steady power and the receiving eye shows whether it can see across the opening, so the light that matters is the one on the side away from the opener.
What each state tells you
- Both steady: the beam is being received. If the door still reverses, the problem is in the opener, not the sensors.
- Receiver blinking: intermittent beam. Usually dust, a partial obstruction or sun.
- Receiver dark, sender steady: nothing is arriving. Misalignment, a cut wire or a dead receiver.
- Both dark: no power reaching the sensors. Check the connection at the motor head before anything else.
The three checks that fix most of them
- Wipe both lenses with a dry cloth. Salt film and spider webs are enough to break the beam in coastal Florida.
- Look for something at floor level between the eyes: a bin, a hose, a bike tyre, a car mirror.
- Re-seat the wiring at the motor head. A terminal screw that worked loose is common after a door has been bumped.
If it only blinks in the afternoon
Low sun straight into the receiver saturates it. The fix is a small shade, or turning the bracket a few degrees rather than moving the sensor. This is a South Florida problem more than a hardware fault.
If it blinks after rain
Water in the housing, or corrosion on the terminals. Dry it, clean the contacts, and if it recurs, replace the pair: a sensor that takes on water will fail again the next storm.
Same-day service across Miami-Dade, Broward and Palm Beach, 100% workmanship guarantee, free estimate. Call (305) 885-8088.
We test the whole safety circuit, not just the sensor, so you do not pay twice for the same symptom.