Error in Parts Diagram
I believe that Appliance Parts Pros is wrong and are basing there omission of the 304475 thermostat on an error in the Whirlpool version of the DE412 parts diagram, which does not list the 304475 thermostat. I have attached two photos below from the DE412 parts manual. The first diagram shows the blower housing thermostats for all the 12 series machines. You will see two cycling thermostats shown for the DE/DG412 machines. The second diagram is specific to the DE412 and for some reason, they omitted the second thermostat (4 on the first diagram). The hi-limit thermostat s attached to the heating element so is on another page in the parts diagram.
Also attached is the electrical diagram of a DE412 again showing the presence of two cycling thermostats and one hi-limit thermostat.
The DE/DG412s are perhaps one of my favorite Maytag dryers. I love the thermostatically-controlled automatic drying design concept for its flexibility in selecting how dry you want your clothes. The electronic-sensing Maytags are excellent, but don't provide the same flexibility in my opinion.
As luck would have it, I've run into a string of three DG412s recently in my neck of the woods, otherwise known as the Land of Maytag Milk and Honey (Des Moines is 35 minutes west of Newton. ) I restored all three DG412s over the past two months. All three had two cycling thermostats. The DE412 would have the same.
I've attached photos of one of my DG412s (before and after) showing the blower housing thermostats (this was a series 7 machine, so it also has the thermal fuse to the left of the thermostats.) Finally, I've attached a photo of my Maytag Plant 2 Dryer Line "re-creation" in my garage!
I'm still not convinced you have a thermostat issue. Can you easily pull your dryer away from the wall and disconnect the exhaust ducting? Then run a load of wet clothes from the washer to see how long it takes? If it runs much faster, then I would look into your ductwork for any obstructions.
Qsd-dan also brings up a good point - check your blower fan and see if its connection to the motor shaft is loose. Your motor might be doing its job but if the blower fan is not connected well, it can lead to poor air flow and cycling of your hi-limit thermostat.
