timer auto cycle doesn't advance

When the timer control is in the automatic cycle it won’t advance. The dryer just keeps running until I manually turn the timer off.
When the timer control is in the timed cycle it counts down and stops correctly.
Is the timer control bad?
Thanks very much.

Here are your parts
http://www.appliancepartspros.com/partsearch/modelsearch.aspx?model=DDE7208MCL

Getting info on GE’s is difficult, they like to keep everything a secret.
You may want to check in the control console to see if they have the wiring diagram in there.
Here is a link to a couple GE wiring diagrams, they will at least give you an idea of how GE does things.
http://www.applianceaid.com/diagrams.html

I doubt it is the timer itself. In timed dry and auto modes the timer motor gets voltage from different circuit paths.

In timed dry power is usually directly from the line.
In auto modes it often gets power through the heating element when the element is turned off. There is usually a resistor in the circuit that reduces the 240 heater volts down to 120 volts for the timer motor. Unfortunately I cannot find that resistor in the parts listing.

You really need a wiring diagram as this unit has a lot of switches.

In the above type dryer if the element is grounded it never shuts off so the auto cycle does not advance.

— Begin quote from denman;352516

Here are your parts
Replacement parts for General Electric DDE7208MCL Electric dryer | AppliancePartsPros.com

Getting info on GE’s is difficult, they like to keep everything a secret.
You may want to check in the control console to see if they have the wiring diagram in there.
Here is a link to a couple GE wiring diagrams, they will at least give you an idea of how GE does things.
http://www.applianceaid.com/diagrams.html

I doubt it is the timer itself. In timed dry and auto modes the timer motor gets voltage from different circuit paths.

In timed dry power is usually directly from the line.
In auto modes it often gets power through the heating element when the element is turned off. There is usually a resistor in the circuit that reduces the 240 heater volts down to 120 volts for the timer motor. Unfortunately I cannot find that resistor in the parts listing.

You really need a wiring diagram as this unit has a lot of switches.

In the above type dryer if the element is grounded it never shuts off so the auto cycle does not advance.

— End quote

Thanks for your reply to my question.
Yesterday I cleaned out the vent duct and the internal airways after reading somewhere that a low flow of hot air could cause a problem with the auto dry cycle and keep the dryer on.
I ran a test with a wet towel in the dryer and using the automatic dry cycle with hight heat. Timer advanced correctly. Then tested with medium heat and timer advanced correctly. Then tested with low heat and timer WOULD NOT ADVANCE.
I checked the resistor in control panel and it measured about 3700 ohms. That matched what was on the wiring schematic inside the control panel.
I am not able to interpret the complete wiring schematic.
In timed cycle the time advances correctly.
So as of now my dryer works in auto cycle when set for high or medium heat. I can’t figure out why the timer won’t advance when in automatic cycle and low heat.
Thank you to anyone that replies!