Garage Door Opener
I have a Craftsman 139.53660SRT1 garage door opener. I bought it used. The button on the wall will open it, but when I go to close it, it goes about a foot, then reverses back to fully open. I have the sensors facing each other, but no green lights.
1. Do I need sensors for this unit to work, it was made in '98. The bulb flashes 5 times after it reverses back. Help please.