Determined it wasn't defrosting properly.
Removed back of fridge and opened electronic control module.
Checked defrost fuse and circuit continuity.
Monitored temperature sensor voltages during operation.
Determined the defrost temp sensor was reading 140F when it should have been 10F.
Removed all food and shelves.
Uncovered refrigerator cooling coils.
Replaced the defrost temperature sensor.
It's been working fine ever since.