The dryer takes 3 cycles to dry. Why?
Many times when a dryer will start and run while the start is pushed but stop the moment you let go is due to a bad centrifugal switch on the motor.
watch this video for more info how this switch works
https://www.youtube.com/watch?v=CaaqRXQERVc
Bill gives a good explanation of how it works. You needn’t do this elaborate of a test. But just know that if the wiring is intact you will need to replace the motor due to the contacts inside the switch being burnt or the switch lever/mechanism being broken.