Abstract: An automotive air conditioning system is provided. The air conditioning system includes an air conditioning compressor. A reservoir having fluid is provided. A pump is interconnected with the reservoir and operatively interconnected with and driven by an engine of a vehicle. The pressure chamber is interconnected with the pump and receives fluid from the pump. A fluid drive element, located relative to the pressure chamber, and interconnected with the air conditioning compressor, converts a passage of pressurized fluid therethrough into mechanical driving force for driving the air conditioning compressor. A regulator maintains a selected level of pressure in the pressure chamber and diverts excess fluid from the pressure chamber to the reservoir so that a constant air conditioning compressor driving speed is maintained.