The Frigidaire Gallery gas dryer we purchased in 2001 has a moisture sensing feature. On that setting it will turn the dryer off when the clothes are dry. It has stopped working, but the timer still works properly. I see online a part # ap3220652 which might have something to do with this problem but do not know if this should be my first step or if there is some other part or loose connection that might be at fault. It is a stacked unit, and the washer was repaired in December. Something may have been jostled, but the sensor has been working until two weeks ago. Is this a user serviceable problem?