Subaru 2004 Forester, Service Manual

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GW-31
GLASS/WINDOW/MIRROR
Rear Window Defogger
17.Rear Window Defogger
A: INSPECTION
CAUTION:
When wiping stain on glass off with cloth, use a
dry and soft cloth and move it in the direction of
heat wire extension to avoid damage to heat
wire.
1) Turn the ignition switch to ON.
2) Turn the defogger switch to ON.
3) Wrap the tips of tester pins with aluminum foil to
avoid damage to heat wire.
4) Measure the voltage at wire center with DC volt-
meter.
Standard voltage:
Approx. 6 V
NOTE:
• If the measured value is 12 volts, heat wire is
open between wire center and positive (+) end.
• If zero volt, heat wire is open between wire cen-
ter and ground.
5) Apply positive lead of voltmeter to positive terminal
of heat wire, and then move the negative lead along
the wire up to negative terminal end. If voltage chang-
es from zero to several volts during movement of
lead, heat wire is open at the voltage change point.
B: REPAIR
1) Clean the broken portion with alcohol or white
gasoline.
2) Mask both side of wire with thin film.
3) Apply conductive silver composition (DUPONT
No. 4817) to broken portion.
4) After repair, check the wire.
(1) Tester probe
(2) Tin foil
(3) Heat wire
(4) PRESS
(1) Center
Voltage Criteria
Approx. 6 V OK
Approx. 12 V or 0 V Broken
GW-00076
(2)
(3)
(4)
(1)
GW-00077
(1)
(1) Broken portion
(2) Masking thin film
(3) Broken wire
(4) Conductive silver composition (DUPONT No.
4817)
GW-00078
(2)
(3)
(4)
(1)