
Originally Posted by
CivicVTi
It will damage the compressor if left untreated, the oil is used to lubricate vital moving parts. This is one of the reasons why the aircon system should be serviced once a year, it also includes relubrication of the compressor.
You can use the blower function safely with the thermostat in the OFF position. If you turn on the thermostat and the refrigerant level is low, the system will shut down automatically in order to preserve the compressor. For cars that have modified wirings to bypass the thermostatic switch that detects low refrigerant level, this is very risky. If the thermostat/aircon system is forced to engage even with low refrigerant, then the compressor may get damaged permanently.