A contactor assembly including a housing, an accessible contactor assembly component, a contact bar, and a module is provided. The accessible contactor assembly component may be disposed within the housing. The contact bar may be electrically connected to the accessible contactor assembly component and translatable between an open and a closed position. The module may be programmed to identify whether the contact bar is in the open or closed position based on detected voltage of the accessible contactor assembly component. The assembly may further include a pair of coil terminals, a pair of power terminals, and a diagnostic terminal arranged for electrical communication with the accessible contactor assembly component. The module may be further programmed to detect whether the contact bar is in the open or closed position responsive to detection of a voltage status of the diagnostic terminal.