Abstract: A universal automotive air conditioning compressor assembly with interchangeable mounting rings and suction and discharge manifolds. The compressor includes a universal casing body which will substitute for a large variety of original equipment compressors. The casing has grooves which removably receive interchangeable mounting rings. Various configurations of mounting rings are provided to match original equipment specifications for a wide variety of vehicle makes. The assembly also may include suction and discharge manifolds which are also interchangeable and which adapt the universal compressor unit to the particular suction and discharge hoses, eg., V-style or pad-style, in the original air conditioning system. Thus, by selecting the appropriate mounting rings and manifold style, a universal compressor is adapted for installation in a specific make and model of automotive air conditioning system.