Your dryer timer will probably not advance towards shutdown unless the clothes are dry. if the control thermostat is not satisfied it will send power to the element. This will stall the motor on the timer through the 3rd wire (orange) on the high limit at the base of the heater. If the heater is bad the control will never get satisfied and shut down, so the motor will continue to not move. Replace the heater or the limit kit whichever is bad and all should be well. The timer is mostly never the problem.