
1.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.

2.If a heater line is burned out between the center point and (+) terminal, the voltmeter will indicate 12V.

3.If a heater line is burned out between the center point and (-) terminal, the voltmeter will indicate 0V.

4.To check for open circuits, slowly move the test lead in the direction that the open circuit seems to exist. Try to find a point where a voltage is generated or changes to 0V. The point where the voltage has changed is the open-circuit point.

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

1.Conductive paint.
2.Paint thinner.
3.Masking tape.
4.Silicone remover.
5.Using a thin brush :Wipe the glass adjacent to the broken heater line, clean with silicone remover and attach the masking tape as shown. Shake the conductive paint container well, and apply three coats with a brush at intervals of about 15 minutes apart. Remove the tape and allow sufficient time for drying before applying power. For a better finish, scrape away excess deposits with a knife after the paint has completely dried. (Allow 24 hours).

Components and Components Location
Rear Glass Defogger SwitchHyundai Tucson (NX4) 2022-2026 Service Manual: Electro Chromic Inside Rear View Mirror
Description and Operation
- Description
Electro Chromic Inside Rear View Mirror
The ECM (Electro Chromatic inside rear view Mirror) is intended dim the
reflecting light in the rear view mirror. The forward facing sensor
detects brightness of the surroundings, while the rearward looking
se ...
Hyundai Tucson (NX4) 2022-2026 Owner's Manual: Electrochromic mirror with
Homelink System
Your vehicle may be equipped with
a Gentex Automatic-Dimming Mirror
with an Integrated HomeLink® Wireless
Control System.
During nighttime driving, this feature
automatically detects and reduces the
rearview mirror’s glare. The HomeLink®
Universal Transceiver allows you to
activat ...