This work presents the basic approaches for building coupled dynamic model of an alternator used for identification of critical locations due to vibrational loads. Numerical model development for every individual component and the assembly of an alternator with finite element method is shown, as well as experimental verification of the numerical models. Modal assurance criterion was used for comparison of experimental and numerical modal parameters. Two numerical models were created for the stator packet. In the first model the stator packet was modeled as a continuum with orthotropic material properties. In the second model each sheet in the stator packet was modeled separately, including friction forces between laminas. ISO 16750-3:2003 standard was used for determining vibrational loads on the alternator when mounted on a piston-driven engine.