While the start knob on dryers is being phased out, if you still own this older model of dryer then you will still need to know how to troubleshoot it. In order to start the dryer, you will need to turn the start knob to kick start the cycle. However, instead of running once you let go of the knob, the dryer stops again. Obviously, you cannot be expected to stand there and hold the knob while the cycle runs. So how do you fix this issue?
The first issue you should inspect, and also the easiest to fix, is the knob itself. If the knob is cracked or broken, it may actually be shutting the cycle off immediately after you let it go. Unfortunately, while the knob is easy to replace, the other causes of this malfunction are not as easy.
If the actual knob on your dryer has checked out, the other two main culprits are the centrifugal switch and the motor relay. Both are activated when you turn that knob. As long as the knob remains engaged, these two parts may work. However, if one is faulty, then it will cease function once the switch is disconnected.
Both the motor relay and the centrifugal switch are located near the motor of your appliance. This means you will need to remove the back panel of your dryer to reach it. Once located, you can test them with a multimeter. Unfortunately, both the motor relay and the centrifugal switch look like pretty nondescript black boxes. This means it can be difficult for the untrained eye to know which one they are working with and thus which one they need to replace. If you have checked the knob, it is highly recommended that you call a professional to investigate the other issues, as they can be a little more tricky.