I have a Maytag Neptune electric dryer model MDE5500AYW. Using sensor dry the timer says 38 minutes, it counts down to 31 min then goes to a 1 minute cooldown and shuts off.

Possible faulty sensor

There is a wetness sensor bar assembly inside the dryer. It looks like a flat hotdog with two metal strips on it. It is near the front of the machine and the clothes have to touch it when they are drying. If the unit is dirty, damaged or disconnected, the sensor wont tell the program to keep running and the unit shuts off. The sensor may have lint or softner on it, may have come disconnected in back. Dont disassemble the drier without unplugging the power first.