Here is a service manual
http://www.servicematters.com/m...ibrary/docs/16023086.pdf

The important part is the timing chart.
You will notice that in timed dry the timer gets power through timer contacts #2 for the entire cycle. On other cycles it gets power from the cycling thermostat at least for part of the cycle. Thermostat shuts off the heater but turns on the timer using the normally open contacts.

Hope this helps!

OK looking at the wiring diagram page 9-14.
The timing chart shows the different timer settings and what contacts are closed at those settings.The timer is shown with all the contacts open. The TEMP SWITCH is shown in the Air only setting.

The first question is does the timer advance when set to timed dry?

You will notice in timed dry contacts 2 are closed for the entire cycle
Your timer motor gets power by the following path: Neutral, WHite, TIMER MOTOR, ORange, timer contacts 2, YeLlow, L1.

Now lets put the timer into Permanent Press at the start of the cycle where timer contacts 2 are open, and we set the temp switch to REG MED DEL. Now the path to get power to the timer motor is Neutral, WHite, TIMER MOTOR, ORange, CYCLING THST contacts ReD, REG MED DEL on the temp switch, BLue, timer contacts 3, timer contacts 4, BLack, L1

In the above the timer gets power when the cycling thermostat is Off (heater switched off). The diagram shows its contacts in the Normaly Closed position and the heater is on in this position. When the termostat gets hot enough it switches to the Normaly Open position the heater shuts off and power for the timer motor goes through the NO contacts. So your timer only gets power when the hreating element is switched off.

You are just trying to get L1 (line 1 is at 120 volts) to Neutral so you have 120 volts supplied to the timer motor.

It may be easier to understand if you print a number of copies of the wiring diagram. The then pretend that the dryer is set to a certain cycle type and temperature setting. Look at the timing chart and mark the contacts which are closed on your print. Then the exercise is to trace a path from L1 to Neutral so it is across the timer motor.

I hope the above helps, guess I should of paid more attention to the communications class when I was in school.