Changed out timer start switch and buzzer still the same.It wilt the almost on each cycle but will keep running,
If you know how to open up the Timer without removing the wires you can see if the contacts are burned or welded together. I clean them up for testing if burned to confirm trouble. Note: some customers will waive repair if you make it run correctly even for a test.
It sounds like either the dryer has a wrinkle free function (WRINKLE PREVENT) that keeps it going until opened, or just as it's supposed to turn off the contact stays connected running the motor and stopping the timer motor from advancing enough to stop both.
With dryer off and timer at the very end of a cycle at the very position you cannot hear the timer motor any longer you can press the start button and see if it starts.