Sears Craftsman - Lights won't operate - door operates fine

Often, there is a relay that controls the light. When the door has been open for several minutes and you break the beam, do you hear a click? If you hear the click, you might be able to trace the wiring between the relay and the fixture and perhaps find a bad connection or solder joint on a printed circuit board.

Otherwise the relay, if there is one, could be bad.

I don't know if Sears still does this but they used to have a heating element to control the delay time on the light. It looked like a big wire wound resistor with 2 forked lugs to fit under 2 screw heads. THe wire would frequently open up and the light would stop working. A quick fix would be to unwrap the wire enough to fit it under the screw head, The real fix was to get a new element. Mine used to go out like clockwork

As I said the older Sears used to do this. I dont know know if they still do.