Dodge Ram Truck 1500-2500-3500. Manual - part 339
1.
Use a scan tool and check for diagnostic trouble
codes (DTCs) related to the A/C-heater control. If
no DTCs are found, go to Step 2. If any DTCs are
found, repair as required, then proceed to Step 2
2. Turn the ignition switch to the On position. Set the
rear window defogger switch in the On position.
The rear window defogger and heated outside rear
view mirror operation can be checked by feeling
the glass surfaces of the rear window or outside
rear view mirrors. A distinct difference in tempera-
ture between the grid lines (1) and the adjacent
clear glass (2) or the mirror glass should be
detected within three to four minutes of operation.
3. If a rear window glass temperature difference is not
detected, use a 12-volt DC voltmeter (4) and con-
tact the rear glass heating grid power feed terminal
A (3) with the positive lead, and the ground termi-
nal B (5) with the negative lead. The voltmeter
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 EBL relay and fuses located in the integrated power module (IPM) in the engine compartment. The
relay and fuses must be tight in their receptacles and all electrical connections must be secure. Refer to the
appropriate wiring information for diagnosis and testing of the ISO-standard relay.
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 in the A/C-heater control.
•
Rear window defogger grid lines (all grid lines would have to be broken, or the power feed or the ground wire
disconnected, for the entire heating grid to be inoperative).
4. If a heated outside rear view mirror glass temperature difference is not detected, use a 12-volt DC voltmeter (4)
and contact the rear view mirror glass heating grid power feed terminal 1 with the positive lead, and the ground
terminal 5 with the negative lead. The voltmeter should read battery voltage. If the voltmeter does not read bat-
tery voltage, check the following:
•
Confirm that the ignition switch is in the On position.
•
Make sure that the rear view mirror glass heating grid feed wire and ground wire are fully connected to the
terminals. Confirm that the ground wire has continuity to ground.
•
Check the heated mirror relay and fuse located in the integrated power module (IPM) in the engine compart-
ment. The relay and fuse must be tight in their receptacles and all electrical connections must be secure. Refer
to the appropriate wiring information for diagnosis and testing of the ISO-standard relay.
When the above steps have been completed and the rear view mirror glass heating grid is still inoperative, one or
more of the following is faulty:
•
Rear window defogger switch in the A/C-heater control.
•
Rear view mirror grids (both the left and right mirror grids would have to had to fail or the power feed or the
ground wire disconnected, for the both mirror grids to be inoperative).
5. If the operation of the EBL system and/or the heated mirror system has been verified but the defogger LED
indicator does not illuminate, replace the A/C-heater control (Refer to 24 - HEATING & AIR CONDITIONING/
CONTROLS/A/C HEATER CONTROL - REMOVAL).
8G - 8
HEATED GLASS - SERVICE INFORMATION
DR/DH