If MR pressure has not increased after a Compressor Fault light illuminates, what else might that indicate?

When the MR pressure does not increase following the illumination of the Compressor Fault light, it strongly suggests that there may be a defective pressure switch. The pressure switch is responsible for monitoring and activating based on the pressure levels within the system. If it is malfunctioning, it can fail to detect and relay the correct operational data, leading to situations where the system does not respond appropriately, resulting in pressure levels not reflecting the compressor's state.

In scenarios like this, it's essential to verify the integrity of the pressure switch to ensure it is functioning correctly, as it plays a pivotal role in the compressor's operational feedback loop. A faulty pressure switch can prevent the compressor from engaging or continuing to operate normally, which is directly related to why the MR pressure remains static despite an obvious fault condition indicated by the light.