If during engine start, the starter valve light doesn't illuminate, what should be fixed before proceeding with the start?

In the context of C-17 engine start procedures, the starter valve light serves an important function. When this light does not illuminate during the engine start sequence, it indicates a potential issue with the starter valve system that could prevent the engine from starting properly.

It is essential to address the problem before proceeding with the start to ensure that all systems are functioning correctly and to prevent possible engine malfunction or damage. Ignoring this indication could lead to an unsuccessful engine start or, worse, a hazardous situation during flight operations.

Consequently, ensuring that the underlying issue is resolved is a critical step in mission readiness and safety. The other options pertain to specific systems or circuits, but none address the necessity of diagnosing and fixing the overarching problem indicated by the absence of the starter valve light.