Abstract: There is illustrated and described a method for joining a composite sheet metal member to an additional component, the composite sheet metal member having at least two outer covering metal sheets and at least one non-metal layer which is arranged between the covering metal sheets and the additional component having at least one outer metal layer, wherein the composite sheet metal member and the additional component are moved so as to overlap each other between two electrodes of a resistance welding unit. In order to be able to join composite sheet metal members in an operationally reliable manner by means of resistance welding, there is provision for an electrically conductive dummy element to be moved into abutment with an outer covering metal sheet and for at least one current path between the two electrodes to be closed by means of an electrically conductive dummy element.