Here are the parts
Replacement parts for 110.66732501 models | AppliancePartsPros.com
See the attachment for the wiring diagram.
Does the timer advance but just not shut off?
When you replaced the heater was it also not shutting off?
Did this unit used to advance/shut off or has it never done this for you?
This timer runs directly off the 240 in timed dry.
Since you have replaced timer, I would unplug the unit and check the wires to the timer motor and that timer switch 0 timer contacts are closed.