Whirlpool Dryer will not start unless set timer switch to Cool Down

[ciphyre]

My Whirlpool dryer will only turn on when I set the timer to cool down. Once I get it running if I switch to a timed heat setting it shuts off. I have been able to get the dryer to heat messing around with the timer switch, so it looks like the dryer can heat, but it doesn't last long and shuts off when I do get it to start to heat. Not sure what defective part could cause these symptoms?

Is it a thermostat or does it have something to do with the timer itself? Or is it the heating element?

Any advice would be great, thanks.

[ciphyre]

Been using the dryer and checking on it, it appears that it is actually drying the cloths on the cool down cycle. So the dryer heats up but only on a cool down setting, anything else and it won't start or continue running.

Would this be the cycle timer on the top of the unit?