Side by side ge fridge. 12 years old. Started making a noise many months ago. Best I can describe is it sounded like a Harley Davidson in the distance. Would last maybe a few minutes then stop. Few days ago the noise was pretty loud, freezer seemed to not be freezing. Turned freezer all the way down overnight. Plugged back in after 8 hours and was very quite, for about three hours, then constant rumble. Traced the noise to the fan motor. I removed the ice maker, lifted the cover on the fan, and the back cover for the coils. There is a metal assembly with glass tubes . I check and it has omhs, so I know the heater is good. At this very moment the freezer is reading 28.7 and falling. The fridge was reading 50 degrees, now down to 46. How can I check the fan for the freezer? What do normal functioning coils look like in the freezer? Mine are going from silver to think frosted white.