How does a murphy switch in a freightliner work for starting it?

A Murphy switch in a Freightliner is a safety device that prevents the engine from starting under certain conditions, such as low oil pressure or high coolant temperature. When these parameters are not within safe limits, the switch interrupts the starting circuit, preventing the starter from engaging. This ensures that the engine is not started in potentially damaging conditions, protecting both the engine and the vehicle. The system typically includes indicators to alert the driver of any issues before attempting to start the engine.