, this electric dryer stopped running while in the middle of drying and would not restart for the customer. When the door was closed, the lights would come on as usual, but when the start button was held to start the dryer, a click could be heard, but nothing else would happen. The time would begin to count down on the display, but obviously it wasn't paying any attention.
Dryers are pretty basic in their operation and thus, the wiring isn't to difficult to follow when looking for a failed component. And on units that utilize an electronic control board for motor control, the wiring changes, but the same dryer parts come into play when looking for a problem. Door switches are common failure points as they will prevent any dryer from starting. These are usually wired to provide the neutral electrical path for the drive motor so voltage will still be present to the motor, just no complete electrical circuit. Some dryers, like this one, use a belt switch to detect when the drum drive belt has failed. If the belt were to break, the switch would open and prevent the motor from starting by opening the L1 side to the motor. But the most common reasons for a dryer to fail, be it the motor not running, or it isn't heating is one of the safety components.
Dryers have several thermal overload devices (TOD's) that are designed to open the electrical circuit in the event of an overheat condition, or possibly prolonged exposure to excessive heat. This heat is rarely the result of a failed control or thermostat, but much more likely due to a blocked, crushed, or otherwise restricted vent connected to the dryers exhaust. Without good air flow to aid in drying your clothes, the dryer drum temperature will climb quickly until the control thermostat shuts off power to the element. If this is allowed to continue, the safety components will continue to be exposed to this excessive heat and will eventually open the circuit. This results in either the dryer won't start, or the dryer won't heat. A dryer parts search should help you find the correct TOD for your make and model.
On this dryer, I held down the start button to verify the failure and heard a click from the control board. Knowing that sound was the drive motor relay closing, I figured I wasn't dealing with a door switch or power problem. Instead, I removed the lower access panel to get to the motor and safety TOD's. After removing the three screws that hold the blower cover in place, I was able to easily get to the motor thermal fuse to do a quick resistance check with my meter. With one wire removed to isolate the component, I did my check and found an open circuit. Looks like I didn't need to go to far to figure this one out.
I removed the old fuse and installed a new thermal fuse in it's place. Reattached the wiring and reinstalled the blower cover and access panel. With the power reapplied and the unit powered up, I held down the start button, but this time it worked. As a final check, I showed the customer the crushed flexible metal vent behind the dryer and explained that it was most likely the cause of this failure. They had recently pulled the unit away from the wall to clean and must have pushed it back a little further than before. My guess is it won't happen again.