Test all of the grid lines in at least two places in order to eliminate the possibility of bridging a break. Test each grid line a few millimeters from the center of the window.
If abnormal test lamp brilliance is apparent on a specific grid line complete the following steps:
Decreasing brilliance on the test lamp indicates a break in the continuity of the grid line. Refer to Defogger and Heated Mirrors in Electrical Diagnosis for the electrical diagnosis of the rear window defogger system.
