Which of the following is an indication of a malfunction in the Switch according to Tower Operator protocols?

A dark Switch detector is a clear indication of a malfunction in the Switch because it signifies that the detector is not detecting the position or status of the Switch. In a properly functioning system, the Switch detector should be lit, indicating that it is operational and effectively communicating the condition of the Switch. When the detector is dark, it can suggest potential failures such as electrical issues, misalignment, or a complete cessation of communication between components, all of which are critical concerns that need immediate attention.

In a well-functioning system, full movement of the Switch is a normal condition, and it typically indicates that the mechanism is operating correctly. A freely moving Stop Arm also denotes proper functionality, as it should be able to move without obstruction when activated. Thus, these scenarios do not indicate a malfunction but rather suggest that the equipment is working as intended.