One of the Stanley safety sensors has a blinking LED while the other is solid or off; door will not close from remote unless wall button is held.

Safety first: Do not operate the door automatically until the safety reversing system is working correctly.

Steps to correct sensor LED fault:

• 1. Realign sensors: Loosen the wing nuts on both Stanley sensor brackets. Rotate and tilt the sensors until the LED on the receiving sensor glows solid. Tighten the nuts while holding alignment.
• 2. Check mounting height: Ensure both sensors are mounted at the same height from the floor (typically 4–6 inches) and not twisted in the brackets.
• 3. Inspect for reflections: Strong sunlight or reflective surfaces can interfere. If the door faces direct sun, angle the sensors slightly inward or install small shades to block glare.
• 4. Verify wiring polarity: At each sensor, confirm the wires are connected to the correct terminals (+ and − if marked). Reverse them if necessary and recheck the LED.
• 5. Test operation: Once both LEDs are solid, test closing the door with the remote. The door should close without holding the wall button.