Open the garage door and remove all the vehicles. Sweep the floor directly underneath where the garage door comes down. Dead leaves, grass clippings and other debris on the floor of the garage door can cause the sensors in the Sears Craftsman garage door opener to malfunction by automatically lifting the door when they sense any of these objects underneath.
Remove any weeds or tall grass growing along the side of the open garage doors; these growths can block the electric eye and cause it to malfunction. The garage door opener will not operate properly if there are any obstructions between the two electric eyes located at either side of the door.
Wipe the electric eye with a soft cloth on a regular basis. A buildup of dirt and dust on one or both of the electric eyes can cause them to malfunction. If the electric eye sensor is blocked by dust or debris, it cannot detect the signal to lift the garage door.