GE Dryer problem

We have a 22 year old GE dryer (model DDE7900BALWH) which has non-functioning Automatic Cycles (both regular and permanent press) but the timed cycle (you set the number of minutes works fine). To use the automatic cycles, one sets the dial between more dry and less dry and the dial is supposed to move to the less dry end until the clothes are dry and the the dryer automatically stops. In our case, the dryer timer dial is not moving for the automatic cycles.
I have a somewhat generic GE (from GE) dryer repair model. It mentions that some models have humidistats by the lint filter (either inside the drum or underneath the lint filter). Our dryer doesn't have a humidistat in either of these places. There are two thermostats there (I assume that both are thermostats) but no humidistat. The thermostats are about 1" inch round devices mounted on the inside front wall of the dryer.
Any ideas on how to fix this dryer would be appreciated. I always assumed that there would be a humidistat somewhere in the dryer since it seems to be drying based on humidity.
David L. Hanson Ye MUST be born again.
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What you have (in all probability) is what I like to call a "fake" auto dry. One of your thermostats will power the timer motor in "auto" mode until it cools back down, then it will power the gas burner/electric element. Once it heats back up, the process is repeated.
Have you looked inside the control console for a wiring diagram? That's generally where they're found in GEs. That may give you a starting point. If you find it, feel free to scan it and e-mail it to me.
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David L. Hanson wrote:

Hi,
A copy:
Dryer Basics - timers and how they work: Timed dry cycles on a timer are the simplest timer cycle. The timer motor receives 120 volts and just advances all the way from where you set it to the off position. Example- You set it for 50 minutes, it will run for 50 minutes and shut off. The AUTO cycle is a little different. The operating thermostat cycles off and the power is redirected to the timer motor to advance the timer to the off position. There is no power to the timer motor until the thermostat cycles the heat off and then that power is directed to the timer motor. If your timer will not advance in timed and auto dry...probably a bad timer or wire. If your timer will not advance in AUTO dryer but will advance in timed dryer...problem is normally not your timer.

Not needed or used on your dryer. The power is shunted through one of the 2 heating elements through a resistor to the timer motor when the auto cycle is used. Check the heating elements, resistor, wiring to and from and the operating thermostats.
http://www.repairclinic.com/referral.asp?R 3&N'6522 Resistr term
http://www.repairclinic.com/referral.asp?R 3&N'6724 Dryer thermostat assembly, L145-15
http://www.repairclinic.com/referral.asp?R 3&N'6725 Dryer thermostat, L135
http://www.repairclinic.com/referral.asp?R 3&N423 Heating element kit, two coils and hardware jeff. Appliance Repair Aid http://www.applianceaid.com /
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Clean the vent that comes off the back of the dryer and goes to the outside. The auto cycle will most likely work then and the clothes will dry faster and more efficiently. A quick check to see if the vent is the problem: disconnect it from the back of the dryer and do a load of clothes. If it works, it's your vent filled with 22 years worth of lint and dirt.
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wrote

The vent is fine - we have only lived in this house for 3+ years (the house is 7 years old). But after doing some more troubleshooting, I found out that the resistor has the correct resistance but one of the heating elements is open. I ordered a new belt and new rear bearing since I will be pulling the drum to replace the heating elements. The current belt and bearing are orginal 22 year old parts. I have only changed two parts - the motor and the door switch.
Thanks, David
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Hi and Happy New Years,
Thankx for the update! jeff. Appliance Repair Aid http://www.applianceaid.com /
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