Chrysler Concorde 2004 Service Manual page 1656

8G - 2 HEATED GLASS
HEATED GLASS (Continued)
Fig. 1 REAR WINDOW DEFOGGER SYSTEM
SCHEMATIC
1 - BCM AND BUTTON LED RELAY CONTROL LINE (MANUAL
TEMPERATURE CONTROL ONLY)
2 - VEHICLE VOLTAGE SUPPLY
3 - GROUND CONNECTOR
4 - REAR WINDOW GRID LINE STRUCTURE
5 - POINT B
6 - MIDPOINT C (TYPICAL)
7 - POINT A
8 - POWER CONNECTOR
OPERATION - WINDOW DEFOGGER
The passenger can push the Rear Widow Defogger
button on the MTC or ATC head to defog the rear
glass (Fig. 2). The system will only operate when the
ignition switch is in the run position. Once the Rear
Widow Defogger button is pushed, the button indica-
tor will light and the system will operate for a period
of time and then automatically turn off. Refer to the
owner's manual for operation of the MTC or ATC sys-
tem.
Fig. 2 ATC CONTROL HEAD
When the rear window defogger relay is ON, cur-
rent is directed to the rear defogger grid lines. The
heated grid lines heat the rear glass to clear the sur-
face of fog or frost.
Circuit protection is provided by a fusible link,
located in the charging circuit, for the heated grid
circuit and by a fuse for the relay control circuit.
The MTC or the ATC head sends a signal to the
BCM, which indicates to the BCM that the operator
wants the rear window grid to heat. An output wire
from the BCM connects to the coil of the rear window
defogger relay. The other side of the coil is connected
to a fuse. The BCM turns on the relay by connecting
the output line of the BCM to vehicle ground. The
relay contacts will then close supplying vehicle power
to the rear window defogger grid.
CAUTION: Grid lines can be damaged or scraped
off with sharp instruments, care should be taken in
cleaning glass or removing foreign materials,
decals or stickers. Normal glass cleaning solvents
or hot water used with rags or toweling is recom-
mended.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - WINDOW
DEFOGGER
Electrically Heated Rear Window Defogger opera-
tion can be easily checked in three steps:
(1) Use ATC or MTC self diagnostics, or the DRB
III scan tool to check fault codes and control button
operation. (Refer to 24 - HEATING & AIR CONDI-
TIONING - DIAGNOSIS AND TESTING - SELF
DIAGNOSTICS) Note, this does not check the EBL
system. There are no fault codes that can check for
the EBL grid, relay, or wiring. Refer to steps 2 and 3
for system tests.
(2) Perform a system test with a voltmeter. (Refer
to 8 - ELECTRICAL/HEATED GLASS - DIAGNOSIS
AND TESTING - SYSTEM TEST)
(3) Check the voltages at the rear grid relay.
(Refer to 8 - ELECTRICAL/HEATED GLASS/REAR
WINDOW DEFOGGER RELAY - DIAGNOSIS AND
TESTING)
DIAGNOSIS AND TESTING - SYSTEM TEST
(1) Start the engine. With the engine running,
push the Rear Window Defogger button on the ATC
or MTC head. The button LED indicator should light.
If the EBL indicator does not light on the MTC
HEAD, then there may be a wiring problem. This
may also indicate that the BCM will not complete the
circuit to ground that is required to energize the EBL
relay coil (non-ATC vehicles only). (Refer to 8 -
ELECTRICAL/HEATED
DEFOGGER RELAY - DIAGNOSIS AND TESTING)
On ATC vehicles, the LED indicator may light when
GLASS/REAR WINDOW
LH