Service Procedures; Rear Glass Heating Grid Repair - Jeep 1997 Grand Cherokee Service Manual

ZG
DIAGNOSIS AND TESTING (Continued)
Defogger Relay
gized position. This terminal supplies battery voltage
to the fuse in the junction block that feeds the rear
glass heating grid and the defogger switch LED indi-
cator. There should be continuity between the cavity
for relay terminal 87 and the rear glass heating grid
and defogger switch LED indicator at all times. If
OK, go to Step 4. If not OK, repair the open circuit
as required.
(4) The coil battery terminal (86) is connected to
the electromagnet in the relay. It is connected to bat-
tery voltage and should be hot at all times. Check for
battery voltage at the cavity for relay terminal 86. If
OK, go to Step 5. If not OK, repair the open circuit to
the PDC fuse as required.
(5) The coil ground terminal (85) is connected to
the electromagnet in the relay. This terminal is pro-
vided with ground by the Body Control Module
(BCM) rear window defogger timer and logic circuitry
to energize the defogger relay. There should be conti-
nuity to the rear window defogger relay control cir-
cuit cavity of the white 24-way BCM wire harness
connector. If OK, use a DRB scan tool and the proper
Diagnostic Procedures manual to test the BCM. If
not OK, repair the open circuit as required.

SERVICE PROCEDURES

REAR GLASS HEATING GRID REPAIR

Repair of the grid lines, bus bars, or pigtail wires
can be accomplished using a Mopar Rear Window
Defogger Repair Kit (P/N 4267922) or equivalent.
WARNING: MATERIALS
REPAIR KIT MAY CAUSE SKIN OR EYE IRRITATION.
THE KIT CONTAINS EPOXY RESIN AND AMINE
TYPE HARDENER, WHICH ARE HARMFUL IF SWAL-
LOWED. AVOID CONTACT WITH THE SKIN AND
EYES. FOR SKIN CONTACT, WASH THE AFFECTED
RELAY CAVITIES RELAY TERMINALS
CONTAINED IN THE
MASKING TAPE
ELECTRICALLY HEATED SYSTEMS
AREAS WITH SOAP AND WATER. FOR CONTACT
WITH THE EYES, FLUSH WITH PLENTY OF WATER.
DO NOT TAKE INTERNALLY. IF TAKEN INTER-
NALLY, INDUCE VOMITING AND CALL A PHYSICIAN
IMMEDIATELY. USE WITH ADEQUATE VENTILA-
TION. DO NOT USE NEAR FIRE OR FLAME. CON-
TAINS FLAMMABLE SOLVENTS. KEEP OUT OF THE
REACH OF CHILDREN.
(1) Mask the repair area so that the conductive
epoxy can be applied neatly. Extend the epoxy appli-
cation onto the grid line or the bus bar on each side
of the break (Fig. 2).
Fig. 2 Grid Line Repair - Typical
(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) For grid line repairs, mask the area to be
repaired with masking tape or a template.
(5) Apply the epoxy through the slit in the mask-
ing tape or template. Overlap both ends of the break
by at least 19 mm (0.75 in.).
(6) For a terminal or pigtail wire replacement,
mask the adjacent areas so the epoxy can be
extended onto the adjacent grid line as well as the
bus bar. Apply a thin layer of epoxy to the area
where the terminal or pigtail wire was fastened and
onto the adjacent grid line.
(7) 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.
(8) Carefully remove the masking tape or tem-
plate.
CAUTION: Do not allow the glass surface to exceed
204° C (400° F) or the glass may fracture.
BREAK GRID LINE
8N - 5