Why is my damper motor operating continuously - opening and closing?

Hi,

It may be due to a faulty refrigerator temperature sensor (supplier example only to show location of part and manufacturer's part number).

Here's an image of the diagnostic test sheet that may help to find out what the problem is. It is for a WRF560 Series refrigerator but I'm not 100% sure that it is applicable to your particular model although it looks very much like the official tech sheet for your model W10398840 A which unfortunately I could only find in Spanish.

(click on image)

FYI In the tech sheet image RC Thermistor = Refrigerator temp sensor.

If it turns out that the temp sensor is the problem, search online using the manufacturer's part number only for the temp sensor, to find other suppliers that may suit you better.

Hopefully a start.