WHIRLPOOL AWZ2303 TUMBLE DRYER ONLY BLO...

It's call a bad thermal cut-out. You should have a thermal cut-out and a high limit thermostat located adjacent to the heating element (usually mounted right on the heating element housing). They both should read a short or fairly low resistance in the case of the thermostat. If the thermal cut-out is blown it is not a resettable device and must be replaced. The tco is usually sold along with the high limit thermostat. It is HIGHLY recommended that you replace BOTH at the same time. DO NOT attempt to bypass any of these devices either. They are there as safety devices to prevent overheating. You could end up with a fire if you do. Now...with all that said, the tco will blow for a reason. Not cleaning the lint trap will contribute to it, but the big item is the ducting. If the vent ducting is clogged you will experience longer dry times and eventually the tco will trip again. Take the time to THOROUGHLY clean and/or replace your vent ducting from the wall all the way to the vent opening outside. In addition, while you have the dryer open THOROUGHLY clean the inside as well. This includes the air baffle where the blower fan is located. Rule of thumb: if you have lint INSIDE the dryer, it's clogged somewhere. Good luck and I hope this helps you.