An electrical connector is soldered or affixed to a conductive element of a glass sheet of a vehicular window via radiation heating of a layer of solder with an infrared radiative heating device. The heating device may include an infrared lamp and a reflector, which functions to direct the radiant energy from the lamp to a target region generally corresponding with the location of the solder layer between the electrical connector and the conductive element. The heating device is operable to rapidly and substantially heat the solder layer to a desired temperature to melt the solder layer, while substantially limiting directing of heat to the glass sheet. The electrical connector may be affixed at a vehicular or modular window assembly plant, such that the glass sheet may be transported from a glass manufacturing plant to the vehicular or modular window assembly plant without the electrical connector.