When the dryer cycle is set and started, the timer won't advance regardless of the type of cycle chosen. Opening the door when the clothes are adequately dry is the only way to use the dryer. I replaced the timer unit and the problem persisted. I am scratching my head as to where I should proceed next. Any help would be greatly appreciated!

Look at the timer that you put in, and sometimes there is a wire to hook up on the timer to make the timer advance. If that is cool. Then here is the way to distinquish if you have a timer problem, or a sensor problem. Turn the dryer on to the timed dry cycle. Lets just say 60 minutes, if it does not move to 50 minutes in 10 minutes you have a bad timer. If it does move, it would most likely be a sensor problem. I see alot of times that the sensor wire vibrates off, so check that, before you buy a sensor. Also, if the wires are both on, get some alcohol, or nail polish remover, and clean the sensor. Sometimes if you use dryer sheets, you can get a buildup on the sensor, and it won't sence. Also check the vent to the outside. Tom ApplianceEducator.com

It looks like there is a brown wire that drives the timer motor that attaches to a circuit board in the head unit (dryness sensor display). I have checked all the wiring, cleaned the sensor in the drum and removed and examined the circuit board. What are the chances that the circuit board in the dryness sensor display is fried? I don't know of any way to tell if its the circuit board is the problem other than to buy a new one and test it out.

Of note, my exhaust goes to a window well which I installed a cover for about the time this issue started. However, it doesn't totally restrict airflow. Any chances this is related to my timer not advancing? I know it sounds crazy but I am starting to run out of ideas.

Thanks so much for everyones help!

I had suggested you try a cycle on time dry. Have you done that???? The reason being, it eliminates any doings with the board, the sensors, and the thermostats. So if the timer does not move then, you have a bad timer. Tom ApplianceEducator.com

I'm not an electrician, but my common sense tells me that it has to be that circuit board. I was kind of baffled when I put in a new timer and put it on a timed cycle and it didn't advance, so that makes sense that the board runs the motor regardless of the timed vs automatic cycle. Any way to test it without trial and error with a new board?