Hello, anyone have any thoughts? The timer knob appears to advance when it's in the 'timed dry' mode but when it's in the automatic more dry/less dry mode the dryer seems to run and never turn off even though the clothes are dry. How does the more dry/less dry mode work? Is there a sensor of some type that tells the timer to run or turn off? If there is a sensor is it inside the timer or is it located some other place in the dryer? Any help would be very much appreciated.

Thank you

Here is a parts breakdown
Replacement parts for GE DBXR453ET5WW | AppliancePartsPros.com

Here is an example wiring diagram
http://www.applianceaid.com/image/geediagram.JPG

Getting any tech info from GE is nearly impossible so the above is just an example.
If you do not have your wiring diagram check inside the control console, they like to put them in there.

How does the more dry/less dry mode work?
The wiring diagram shows the dryer set to normal heat and timed dry.
When the upper HEATER (see wiring diagram) shuts off, it no longer draws current so you get L2 voltage on the left hand side of the HEATER. This is 240 volts, it is dropped to 120 volts by the RESISTOR and this powers the timer motor. The TX contacts are open in auto cycles.

Is there a sensor of some type that tells the timer to run or turn off?
No, see above

So if the HEATER is open or grounded you will not have timer advance.
Also if the RESISTOR is blown.