Heat Wire Inspection

CAUTION: When wiping off the stain on glass with cloth, use a dry and soft cloth and move it in the direction of the heat wire extension to avoid damage to the heat wire.

Fig 1: Identifying Liquid Crystal Thermograph Sheet And Separate Line

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Inspect the following inspection tools.
- Liquid crystal thermograph sheet (size: approx. 300 300 mm (11.8 11.8 in), heat sensing temperature: approx. 35 - 40°C (95 - 104°F))
- Aluminum foil
Turn the ignition switch to ON.
Turn the defogger switch to ON.
Push the liquid crystal thermograph sheet on to the outer surface of the rear glass.
NOTE: Use the liquid crystal thermograph sheet to each section divided by parting lines.

Check the color of the liquid crystal thermograph sheet to identify the faulty heat wire.

Liquid crystal thermograph sheet	Criteria
Changed (red → blue)	Normal operation
No change (black)	Open

NOTE:

If the response of the liquid crystal thermograph sheet is not sufficient, try the inspection on the inner surfaces of the glass.
The time until color change depends on the glass surface temperature.

Wrap the aluminum foil around the tip of each tester probe and push them on to the faulty heat wire.

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To both ends of the section that has been found to include an open in the step 5), apply the tester positive (+) probe and the negative (-) probe.
Slowly move the negative (-) tester probe along the heat wire. While moving the tester probe, find an open point where the voltage reading changes from 0.

Courtesy of SUBARU OF AMERICA, INC.
Repair the heat wire that determines the place of the open circuit. Refer to REPAIR