Chrysler PT Cruiser Service & Repair Manual page 394

8G - 12 HEATED WINDOW DEFOGGER
DEFOGGER SWITCH (Continued)
(3) Using a voltmeter, check for battery voltage at
Pin 1 and 2 (Fig. 3).
Fig. 3 Rear Window Defogger Switch Harness
Connector
REAR WINDOW DEFOGGER SWITCH AND
HARNESS CONNECTOR PIN CALL-OUT
PIN
1 FUSED B+
2 FUSED IGNITION SWITCH OUTPUT
(RUN)
3 GROUND
4 PANEL LAMPS DRIVER
5 PANEL LAMPS DRIVER
(a) If OK, go to Step 4.
(b) If NOT OK, check fuse 7 in the fuse block
and the 40 Amp cartridge fuse in the Power Distri-
bution Center (PDC). If fuses are OK, check wiring
circuit. Refer to Wiring Diagrams.
(4) Check Pin 5, with switch in the ON position
there should be battery voltage and no voltage in the
OFF position.
(a) If OK, go to Step 5.
(b) If NOT OK, no voltage in the ON position or
voltage in the OFF position. Replace the switch.
(5) Press switch to ON position. The indicator
lamp should come on and remain on for approxi-
mately 10 minutes. If the indicator lamp fails to light
or no voltage is present for approximately 10 min-
utes. Replace Rear Window Defogger Switch. Refer to
Instrument Panel Systems, Accessory Switch Bezel
Removal and Installation.
BENCH TESTING
(1) First remove switch. Refer to Instrument Panel
Systems, Accessory Switch Bezel Removal and Instal-
lation.
(2) With switch removed from vehicle, use a
jumper wire and connect a 12 volt supply to Pin 1
and 2. Using a third jumper wire, ground Pin 3.
FUNCTION
Refer to (Fig. 4) and the Rear Window Defogger
Switch and Harness Connector Pin Call-Out table.
Fig. 4 Rear Window Defogger Switch Connector
(3) Follow the same procedures used for IN-VEHI-
CLE TESTING, except for step Step 2.
REAR WINDOW DEFOGGER
GRID
DIAGNOSIS AND TESTING
GRID LINES
The horizontal grid lines and vertical bus bar lines
printed and fired on the inside surface of rear win-
dow glass comprise an electrical parallel circuit. The
electrically conductive lines are composed of a silver-
ceramic material which when fired on glass becomes
bonded to the glass and is highly resistant to abra-
sion. It is possible however, that a break may occur
in an individual grid line resulting in no current flow
through the line. To detect breaks in grid lines the
following procedure is required:
(1) Turn ignition ON and turn control switch to
ON. The LED should come on.
(2) Using a DC voltmeter with 0-15 volt range,
contact terminal (B) with the negative lead of the
voltmeter. With the positive lead of the voltmeter,
contact terminal (A). The voltmeter should read
10-14 volts. A lower voltage reading indicates a poor
connection in the feed or the ground circuit.
(3) With the negative lead of the voltmeter, contact
a good body ground point. The voltage reading should
not change.
(4) Connect the negative lead of the voltmeter to
terminal (B) and touch each grid line at Mid-Point
with the positive lead. A reading of:
• Approximately 6 volts indicates the line is OK.
• 0 volts indicates a break in line between Mid-
Point (C) and terminal (A).
PT