My side-by-side Amana SBD20MW has been working well for over 10 years. Suddenly, the following change has taken place: Everything is starting to warm up. The freezer is thawing and the refrigerator has reached room temp. Inside the refrigerator I hear nothing and do not feel any cool air circulating. In thr freezer I do hear the continual sound of a motor, but feel minimal (if any) air circulating. Under the refrigerator the fan that blows around the drip pan is working and I do feel the air movement. I just tried manually turning the defrost timer to defrost and all the motors stopped (as I assume they should). I'm feeling the back of the freezer and don't feel any warmth or see any glow. Any thoughts on how to diagnose and resolve this problem?

It turned out to be the defrost timer. Thanks for your thoughts. Len