Dryer wont start

[centralappliance]

I looked at an Inglis dryer made by whirlpool for a lady and it wont start. She said it would not shut off one day then the next time she went to use it it would not run.

So far I pulled the back off and both thermostats are OK, the thermal fuse is OK, the element is OK, the door switch is OK, the motor spins freely. I am a little confused about the exaust thermistor as it has 4 leads coming off it. 2 have continuity and the other 2 do not.

Could this thermistor be the problem? I forgot to check the push switch and also I was thinking the motor relay could also cause this. Is there something common? Can someone shed some light. I am also wondering why it would not shut off to begin with.

Model IH80000

[JWWebster]

The 2 smaller wires are a heater that changes the resistance so that the heat will shut down faster for delicate and perma press. The start switch was probably fried together, that was allowed by the consumer (because opening the door shuts it off and does not constitute a repair guy to come out) till it finally quit. Seen it. Check the start switch.
My postman was telling me his dryer quit. One day he brought it by and we worked on it,cleaned it out real good,it was full of lint. Replaced the blown fuse. When I tried it I closed the door and it started by itself. I asked him about that and he said oh yeah its been doing that a while, we have to open the door to get it to stop. The small black switch comes out easily by giving it a twist after releasing its locking tab and removing the knob. When he saw how easy it was to replace it he told me man I could not figure out how in the hell that switch comes out.  

[jumptrout51]

The control thermostat(4 wires) is not the problem.
Verify 220 volts to the dryer. Check that start switch.
The not shutting off,then not starting sounds like a bad timer if 220 power and start switch check out..