The objective of this paper is to develop a model for the dynamics of an automotive air conditioning system. The air conditioning system consists of a variable displacement compressor, a condenser, an expansion orifice, an evaporator and a control valve. A physically motivated sixth order perturbation model is described including a linearization of system components. The parameters of the model are optimized on a component-by-component basis and optimized component models are interconnected to represent the overall system. A demonstration of the modeling/optimization process is presented for a representative set of operating conditions.