Final answer:
The main power switch or circuit breaker needs to be turned up before the master warning control (MWC) light controls will work.
Step-by-step explanation:
In order for the master warning control (MWC) light controls to work, the light switch that needs to be turned up is the main power switch or circuit breaker.
This is because the master warning control (MWC) light is typically part of the electrical system in a building, and it requires power to operate.
By turning on the main power switch or circuit breaker, you ensure that the electrical system is energized, allowing the MWC light controls to work.