Heated Glass Element: Service and Repair

Rear Window Defogger Inspection And Repair

Defogger Switch Inspection

Use a circuit tester to check defogger switch for continuity.

If switch has no continuity between terminals, replace.







Defogger Wire Inspection

NOTE:
- When cleaning rear window glass, use a dry cloth to wipe it along wire direction.
- When cleaning glass, do not use detergent or abrasive-containing glass cleaner.
- When measuring wire voltage, use a tester with negative tester probe (3) wrapped with a tin foil (2) which should be held down on heat wire (1) by finger pressure.







1. Checking wire damage
a. Turn main switch to ON.
b. Turn defogger switch ON.
c. Use a voltmeter (1) to check voltage at the center (2) of each heat wire, as shown.
If measured voltage is 10 V, wire must be damaged between its center and positive end.
If voltage is zero, wire must be damaged between its center and ground.

Voltage between center and each heat wire







2. Locating damage in wire







a. Touch voltmeter positive (+) lead to heat wire positive terminal end.
b. Touch voltmeter negative (-) lead with a foil strip to heat wire positive terminal end, then move it along wire to the negative terminal end.
c. The place where voltmeter fluctuates from zero to several volts is where there is damage.

NOTE: If heat wire is free from damage, voltmeter should indicate 12 V at heat wire positive terminal end and its indication should decrease gradually toward zero at the other terminal (ground).

Defogger Circuit Repair

1. Clean broken wire (3) tips and its surrounding area with grease, wax and silicone remover.
2. Apply masking tape (1) at both upper and lower sides of heat wire to be repaired.
3. Apply commercially-available repair agent with a fine-tip brush.
4. Two to three minutes later, remove masking tapes previously applied.







5. Leave repaired heat wire as it is for at least 24 hours before operating defogger again.