2006 Hyundai Elantra

Fig. 2: Using Tester Probe With Tin Foil Courtesy of HYUNDAI MOTOR CO. Turn on the defogger switch and use a voltmeter to measure the voltage of each heater line at the glass center point. If a voltage of approximately 6V is indicated by the voltmeter, the heater line of the rear window is considered satisfactory. Fig. 3: Measuring Voltage Of Each Heater Line At Glass Center Point (6 Volts) Courtesy of HYUNDAI MOTOR CO. If a heater line is burned out between the center point and (+) terminal, the voltmeter will indicate 12V.