Chrysler Concorde 1993, Руководство по обслуживанию, Страница: 362 / 820

(6) Steps (3) and (4) or (5) above will confirm system
operation. Indicator light illumination means that there
is power available at the output of the relay only, and
does not necessarily verify system operation.
(7) If turning the switch ON produced no distinct
current draw on the ammeter the problem should be
isolated in the following manner:
(a) Confirm the ignition switch is ON.
(b) Ensure that the heated rear glass feed wire is
connected to the terminal or pigtail and that the
ground wire is in fact grounded.
(c) Ensure that the fusible link and control cir-
cuit fuse is operational and all electrical connec-
tions are secure.
(8) When the above steps have been completed and
the system is still inoperative, one or more of the fol-
lowing is defective:
(a) Control switch or timer relay.
(b) Rear window grid lines, all grid lines would
have to be broken or one of the feed wires are not
connected for the system to be inoperative.
(9) If turning the switch ON produces severe volt-
meter deflection, the circuit should be closely
checked for a shorting condition.
(10) If the system operation has been verified but
indicator bulb does not light, service the A/C heater
or ATC controls.
(11) For detailed wiring information, refer to group
8W, Wiring Diagrams.
GRID TEST
The horizontal grid lines and vertical bus bar lines
printed and fired on inside surface of rear window
glass (Fig. 4) comprise an electrical parallel circuit.
The electrically conductive lines are composed of a
silver-ceramic material which when fired on glass be-
comes bonded to the glass and is highly resistant to
abrasion. It is possible, however, that a break may
occur in an individual grid line resulting in no cur-
rent 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 indicator light should come on.
(2) Using a DC voltmeter with 0-15 volt range,
contact terminal B with negative lead of voltmeter.
With positive lead of voltmeter, contact terminal A
(Fig. 4). The voltmeter should read 10-14 volts. A
lower voltage reading indicates a poor ground con-
nection.
(3) With negative lead of voltmeter, contact a good
body ground point. The voltage reading should not
change.
(4) Connect negative lead of voltmeter to terminal B
and touch each grid line at Mid-Point with Positive
lead. A reading of approximately 6 volts indicates a line
is good. A reading of 0 volts indicates a break in line
between Mid-Point C and terminal A. A reading of
10-14 volts indicates a break between Mid-Point C and
terminal B. Move toward break and voltage will change
as soon as break is crossed (Figs. 4 and 5).
CONTROL SWITCH AND TIMER RELAY TEST
Vehicles with ATC heater will have to be tested
with DRB II. The Body Diagnostic Procedures Man-
ual will have to be used.
Vehicles with manual A/C heater, the control
switch and timer relay may be tested in the vehicle
or on the bench.
IN—VEHICLE TESTING
(1) Remove the control switch from console and do
not disconnect control switch.
(2) Turn ignition ON. Turn defogger ON.
Fig. 4 Grid Line Test
Fig. 5 Systems Electrical Circuit
8N - 2 REAR WINDOW DEFOGGER