Windshield Glass Does Not Heat

Disconnect connector "A" at alternator and connectors "C" and "D" to rear window. Measure resistance between terminals "A" and "C" of connector "A" for left side of windshield and "B" and "C" for right side (see illustration). If resistance is less than seven or more than 20 ohms, check wire numbers 70 Red, 71 White and 72 Dk. Green and windshield for shorts or open circuits. If tests are satisfactory, check alternator output. See Motorcraft High Voltage Alternator in ELECTRICAL Section  .