Printed Rear Window Defogger
Repair Procedures
Inspection

Turn on the defogger switch and use a voltmeter to measure the voltage of each heater line at the center of the glass. If the voltmeter reads 6 V at the live line, the rear window line is in good condition.

If the conductive line is broken between the center section and the (+) terminal, the voltmeter will read 12 V.

If the conductive line is broken between the center section and the (-) terminal, the voltmeter will read 0 V.

To check for open circuits, slowly move the test lead along the section where an open circuit is suspected. Try to find the point where the voltage changes to 0 V. The point where the voltage changed is the open circuit point.

Using an ohmmeter, measure the resistance of each heater line between the terminal and the center of the grid line, and between the same terminal and the center of an adjacent heater line. The section with the broken heater line will have twice the resistance of the other sections. In the affected section, move the test lead to the position where the resistance changes sharply.

Repair Broken Heater Line
Prepare the following items:
Conductive paint.
Paint thinner.
Insulating tape.
Silicone remover.
Using a fine-tipped brush:
Clean the glass near the broken heater line, clean with silicone remover and attach masking tape as shown in the illustration. Shake the conductive paint container and apply three coats with a brush at intervals of approximately 15 minutes. Remove the tape and allow sufficient drying time before applying force. For a better finish, scrape off excess paint with a knife after the paint has completely dried (allow 24 hours).

Test yourself
A quick Kia Rio YB quiz: every answer comes with an explanation and a link to the manual page.