We used the diagnostic tool on this site to identify the problem pretty easily. it also turns out that the cause was also responsible for other problems that we were having with frost buildup in the freezer and low ice cube production. I ordered the two parts that were the most likely needed to be replaced. When installing the fan motor we discovered just how severely the freezer had frosted up behind the back freezer panel. After defrosting, replacing the fan motor, and the capacitor, all our issues were solved. Both parts were easy to replace thanks to the videos on this site. We had thought we were going to have to replace the whole refrigerator but for less than $100 our old one is now running perfectly.