Chrysler PT Cruiser. Manual - part 488

The EBL system will automatically shut off if the

ignition switch is turned to the Off position, or it can
be turned off manually by depressing the defogger
switch a second time.

DIAGNOSIS AND TESTING

REAR WINDOW DEFOGGER SYSTEM

NOTE: Illumination of the defogger switch indicator
lamp means that there is electrical current available
at the output of the rear window defogger logic cir-
cuitry, but does not confirm that the electrical cur-
rent is reaching the rear glass heating grid lines.

NOTE: For circuit descriptions and diagrams of the
rear window defogger system, refer to 8W - WIRING
DIAGRAM INFORMATION.

Operation of the electrical backlight (EBL) system

can be confirmed by the following:

(1) Turn the ignition switch to the On position. Set

the defogger switch in the On position. The rear win-
dow defogger operation can be checked by feeling the
rear window glass. A distinct difference in tempera-
ture between the grid lines and the adjacent clear
glass can be detected within three to four minutes of
operation.

(2) If a temperature difference is not detected, use

a 12-volt DC voltmeter and contact the rear glass
heating grid terminal B with the negative lead, and
terminal A with the positive lead (Fig. 2). The volt-
meter should read battery voltage. If the voltmeter
does not read battery voltage, check the following:

• Confirm that the ignition switch is in the On

position.

• Make sure that the rear glass heating grid feed

wire and ground wire are connected to the terminals.
Confirm that the ground wire has continuity to
ground.

• Check the circuit fuse located in the power dis-

tribution center (PDC) and the control circuit fuse in
the junction block (JB). The fuses must be tight in
their receptacles and all electrical connections must
be secure.

(3) When the above steps have been completed and

the rear glass heating grid is still inoperative, one or
more of the following is faulty:

• Rear window defogger switch.

• Rear window defogger grid lines (all grid lines

would have to be broken, or the power feed or ground
wire disconnected, for the entire heating grid to be
inoperative).

(4) If broken defogger grid lines are suspected, use

a 12-volt DC voltmeter and contact terminal B with
the negative lead and each rear glass heating grid
line at it’s mid-point with the positive lead. The volt-
meter should read approximately 6 volts at each grid
line mid-point C. If the voltmeter does not read
approximately 6 volts, repair the open grid line(s)
(Refer to 8 - ELECTRICAL/HEATED GLASS/REAR
WINDOW DEFOGGER GRID - STANDARD PROCE-
DURE).

Fig. 1 Rear Window Defogger Switch

1 - ACCESSORY SWITCH BEZEL

8G - 2

HEATED GLASS

HEATED GLASS (Continued)

REAR WINDOW DEFOGGER
SWITCH

DESCRIPTION

The switch for the EBL system contains the control

and timing circuitry. The rear window defogger
switch is located in the accessory switch bezel (Fig. 3)
on the instrument panel.

When the rear window defogger switch is turned to

the ON position, current is directed to the rear defog-
ger grid lines and the heated power mirrors (if
equipped). The heated grid lines heat the glass to
help clear the surface of fog or frost.

OPERATION

Depressing the rear window defogger switch ener-

gizes the integral rear window defogger relay, which
provides electrical current to the rear window defog-
ger grid and the outside rear view mirror heating
grids (when equipped). An amber indicator lamp in
the defogger switch illuminates to indicate when the
EBL system is On.

The rear window defogger switch and indicator

lamp cannot be repaired and, if faulty or damaged,
the rear window defogger switch must be replaced.

DIAGNOSIS AND TESTING

REAR WINDOW DEFOGGER SWITCH

WARNING: On vehicles equipped with airbags, dis-
able the airbag system before attempting any steer-
ing wheel, steering column, or instrument panel
component diagnosis or service. Disconnect and
isolate the battery negative (ground) cable, then
wait two minutes for the airbag system capacitor to
discharge before performing further diagnosis or
service. This is the only sure way to disable the air-
bag system. Failure to take the proper precautions
could result in an accidental airbag deployment and
possible personal injury.

NOTE: The rear window defogger switch may be
tested in the vehicle or out of the vehicle, on a
bench.

Fig. 2 Rear Glass Grid Line Test - Typical

1 - REAR WINDOW DEFOGGER
2 - BUS BARS
3 - VOLTAGE FEED “A”
4 - VOLTMETER
5 - PICK-UP LEADS
6 - C.H.M.S.L. TRIM COVER
7 - PARCEL SHELF
8 - GROUND “B”
9 - MID-POINT “C”

Fig. 3 Rear Window Defogger Switch

1 - ACCESSORY SWITCH BEZEL

HEATED GLASS

8G - 3

HEATED GLASS (Continued)

NOTE: For circuit descriptions and diagrams of the
rear window defogger system, refer to 8W - WIRING
DIAGRAM INFORMATION.

IN-VEHICLE TESTING

(1) Remove the rear window defogger switch from

the instrument panel, but leave the switch connected
(Refer to 23 - BODY/INSTRUMENT PANEL/ACCES-
SORY SWITCH BEZEL - REMOVAL).

(2) Turn the ignition switch ON.
(3) Using a voltmeter, check for battery voltage at

Pin 1 and 2 of the rear window defogger switch (Fig.
4).

REAR WINDOW DEFOGGER SWITCH AND

HARNESS CONNECTOR PIN CALL-OUT

PIN

FUNCTION

FUSED B+

FUSED IGNITION SWITCH OUTPUT
(RUN)

GROUND

PANEL LAMPS DRIVER

(a) If OK, go to Step 4.
(b) If NOT OK, check the 10 Amp fuse 6 in the

fuse block and the 40 Amp fuse 8 in the power dis-
tribution center (PDC). If fuses are OK, check the
wiring circuits. Refer to 8W - WIRING DIAGRAM
INFORMATION.

(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 rear win-
dow defogger switch (Refer to 23 - BODY/INSTRU-
MENT PANEL/ACCESSORY SWITCH BEZEL -
INSTALLATION).
(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, replace the rear window
defogger switch (Refer to 23 - BODY/INSTRUMENT
PANEL/ACCESSORY SWITCH BEZEL - INSTALLA-
TION).

BENCH TESTING

(1) Remove the rear window defogger switch (Refer

to 23 - BODY/INSTRUMENT PANEL/ACCESSORY
SWITCH BEZEL - REMOVAL).

(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.
Refer to (Fig. 5) and the Rear Window Defogger
Switch and Harness Connector Pin Call-Out table.

(3) Follow the same procedures used for IN-VEHI-

CLE TESTING, except for step Step 2.

Fig. 4 Rear Window Defogger Switch Harness

Connector

Fig. 5 Rear Window Defogger Switch Connector

8G - 4

HEATED GLASS

REAR WINDOW DEFOGGER SWITCH (Continued)

REAR WINDOW DEFOGGER
GRID

STANDARD PROCEDURE

GRID LINE AND TERMINAL REPAIR

REAR WINDOW DEFOGGER GRID LINE REPAIR

WARNING: Materials contained in the Repair Kit
(Part Number 04549275) may cause skin or eye irri-
tation. The kit contains epoxy resin and amine type
hardener, which are harmful if swallowed. Avoid
contact with the skin and eyes. For skin contact,
wash the affected areas with soap and water. For
contact with the eyes, flush with plenty of water. Do
not take internally. If taken internally, induce vomit-
ing and call a physician immediately. Use with ade-
quate ventilation. Do not use near fire or flame.
Contains flammable solvents. Keep out of the reach
of children. Failure to follow the warnings could
result in possible personal injury or death.

Repair of the rear glass heating grid lines and bus

bars can be accomplished using the Mopar

t Rear

Window

Defogger

Repair

Kit

(Part

Number

04549275) or equivalent.

(1) Mask the repair area with masking tape or use

a template so that the conductive epoxy can be
applied neatly (Fig. 6). Extend the epoxy application
onto the grid line or the bus bar on each side of the
break.

(2) Follow the instructions in the repair kit for

preparing the damaged area.

(3) Remove the package separator clamp and mix

the two conductive epoxy components thoroughly
within the packaging. Fold the package in half and
cut the center corner to dispense the epoxy.

(4) Apply the epoxy through the slit in the mask-

ing tape or template. Overlap both ends of the break
by at least 19 millimeters (0.75 inch).

(5) Apply a thin layer of conductive epoxy to the

terminal or bare wire end of the pigtail and place it
in the proper location on the bus bar. To prevent the
terminal or pigtail wire from moving while the epoxy
is curing, it must be wedged or clamped.

(6) Carefully remove the masking tape or tem-

plate.

CAUTION: Do not allow the glass surface to exceed
204° C (400° F) when using a heat gun, or the glass
may fracture.

(7) Allow the epoxy to cure 24 hours at room tem-

perature, or carefully use a heat gun for fifteen min-

utes. When using a heat gun, hold it approximately
25.4 centimeters (10 inches) from the repair and do
not allow the glass surface to exceed 204° C (400° F).

(8) After the conductive epoxy is properly cured,

check the operation of the rear window defogger
glass heating grid.

REAR WINDOW DEFOGGER GRID TERMINAL REPAIR - HARD
TOP MODELS

Repair of the rear glass heating grid terminal(s) on

hard top models can be accomplished using the
Mopar

t Rear Window Defogger Repair Kit (Part

Number 04549275) or equivalent.

(1) If the grid terminal(s) is broken and a portion

of the terminal is still attached to the heating grid,
remove the portion of the clip remaining in the wire
harness connector(s).

(2) Mask the areas so the conductive epoxy can be

extended onto the adjacent grid line(s) as well as the
bus bar.

(3) Apply a thin layer of conductive epoxy to the

area where the terminal(s) where fastened and to the
adjacent grid line(s).

Fig. 6 Grid Line Repair

1 - BREAK
2 - GRID LINE
3 - MASKING TAPE

HEATED GLASS

8G - 5

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