Subaru Impreza 2003 Service Manual page 3031

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.
(1)
(1) Tester probe
(2) Aluminum foil
(3) Heat wire
(4) Press
4) Measure the voltage at wire center (A) with DC
voltmeter.
Standard voltage:
Approx. 6 V
Voltage
Approx. 6 V
Approx. 12 V or 0 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.
REAR WINDOW DEFOGGER
(4)
(3)
(2)
GW-00076
(1)
GW-00077
Criteria
OK
Broken
GW-31
5) Apply positive lead of voltmeter to positive termi-
nal of voltmeter, and then move the negative lead
along the wire up to negative terminal end. If volt-
age changes 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.
(2)
(1) Broken portion
(2) Masking thin film
(3) Broken wire
(4) Conductive silver composition (DUPONT No.4817)
4) After repair, check the wire.
GLASS/WINDOWS/MIRRORS
(1)
(3)
(4)
GW-00078