Turn on the rear window defroster.
Pic. 7.90. Checking the heated rear window filament
Attention! Touching the rear window heating filament with the probe of the tester may damage the filament. Wrap aluminum foil around the end of the probe and test the thread by touching it with the foil (pic. 7.90);
Pic. 7.91. Connecting the tester probe to the ends of the thread
Connect the positive tester lead to the positive end of each strand and the negative lead to the body ground (pic. 7.91).
By moving the positive probe from the positive end of the thread to the negative end, make sure that the voltage decreases accordingly.
If the voltage changes rapidly, the filament is faulty. Repair thread.