What is the most obvious symptom of a short to ground?

A blown fuse is the most obvious symptom of a short to ground because it serves as a protective measure in an electrical circuit. When a short to ground occurs, it creates an unintended path for electrical current, causing an increase in current flow beyond the fuse's rated limit. The fuse is designed to break the circuit to prevent further damage, which results in the fuse blowing. This action is a defensive response to protect the wiring and connected components from overheating, fire, and excessive current that could lead to more severe issues.

In contrast, burnt wires may indicate various issues, including prolonged overheating, but are not as immediate or obvious as a blown fuse. Overheating of a motor could stem from multiple causes, such as mechanical strain or insufficient airflow, rather than specifically pointing to a short to ground. Sparking connections often suggest poor contact or arcing, which could occur for various reasons and may not directly highlight a short to ground condition. Thus, the blown fuse distinctly signals the occurrence of a short circuit, making it the clearest indicator in this scenario.