Heated Glass - Service Information

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 recommended.

The rear window defogger system, also known as electric backlight (EBL), consists of two vertical bus bars (1) and a series of grid lines (2) fired onto the inside surface of the rear window (3).

The EBL system is turned on or off by a push-button switch located in the A/C-heater control. Refer to

NOTE: ATC control shown. MTC control similar.

The electric backlight (EBL) system is controlled by a momentary push-button switch inside the mode control knob (4) on the A/C-heater control (1) located in the instrument panel center bezel. When the rear window defogger switch is pressed to the On position with the ignition switch in RUN, the switch sends a request signal over the CAN-IHS bus to the totally integrated power module (TIPM), which provides a ground path to energize the coil in the EBL relay. When energized, the EBL relay provides battery current through a fuse to the rear window defogger grid lines and to the heated side view mirrors, when equipped. The grid lines heat the glass to help clear the rear window and side mirror surfaces of fog or frost.

An amber indicator in the mode control knob will illuminate to indicate when the EBL system is operating.

NOTE: The EBL system turns off automatically after 10 minutes of initial operation. Each following activation cycle of the EBL system will last 5 minutes.

The EBL system will be automatically turned off after an initial programmed time interval of about 10 minutes as long as the ignition switch is in RUN. After the initial time interval has expired, if the rear window defogger switch is pressed to the On position again during the same ignition cycle, the EBL system will automatically turn off after about 5 minutes. The EBL system will also turn off if the ignition switch is turned to any position other than RUN or by manually pressing the rear window defogger switch a second time.

Repair of the rear window defogger grid lines, bus bars, terminals or pigtail wires can be accomplished using the Mopar® Rear Window Defogger Repair Kit (Part Number 04549275) or equivalent. See STANDARD

Circuit protection for the EBL system is provided by fuse 13 located in the TIPM.

The rear window defogger (EBL) relay (1) is an International Standards Organization (ISO)-type relay. Relays conforming to the ISO specifications have common physical dimensions, current capacities, terminal functions and patterns (2). The EBL relay is a electromechanical device that switches fused battery current to the rear window defogger grid and to the outside rear view mirror heating grids, when equipped. The EBL relay is energized when the relay coil is provided a ground path by the control circuitry within the totally integrated power module (TIPM).

The EBL relay is located in the TIPM inside the engine compartment.

The rear window defogger (EBL) relay is an electromechanical switch that uses a low current input controlled by the totally integrated power module (TIPM) to control the high current output to the rear window defogger grid lines and to the heated outside mirrors, when equipped. The movable, common feed relay contact is held against the fixed, normally closed relay contact by spring pressure. When the electromagnetic relay coil is energized, it draws the movable common feed relay contact away from the fixed, normally closed relay contact and, holds it against the fixed, normally open relay contact. This action allows high current to flow to the rear window defogger grid lines.

When the relay coil is de-energized, spring pressure returns the movable relay contact back against the fixed, normally closed contact point. The resistor or diode is connected in parallel with the relay coil, and helps to dissipate voltage spikes and electromagnetic interference that can be generated as the electromagnetic field of the relay coil collapses.

The EBL relay terminals are connected to the vehicle electrical system through a receptacle in the TIPM located in the engine compartment. The inputs and outputs of the EBL relay include:

Terminal (30) receives battery current at all times. Terminal (85) receives a ground through the EBL control circuit of the TIPM only when the module electronically pulls the circuit to ground. Terminal (86) receives battery current at all times. Terminal (87) provides battery current to the rear window defogger grid and to the heated outside mirrors, only when the EBL relay coil is energized. Terminal (87A) is not connected to any circuit in this application, but provides a battery current output only when the EBL relay coil is de-energized.

The EBL relay cannot be repaired and must be replaced if inoperative or damaged. Refer to the appropriate wiring information for diagnosis and testing of the ISO relay and for complete rear window defogger (EBL) wiring diagrams.

1. Disconnect and isolate the negative battery cable. 2. Open the cover on the totally integrated power module (TIPM) (1) located in the engine compartment.

NOTE: Refer to the fuse and relay map on the inside of the TIPM cover for EBL relay location.

3. Remove the EBL relay (2) from the TIPM.

NOTE: Refer to the fuse and relay map on the inside of the totally integrated power module (TIPM) cover for EBL relay location.

1. Position the EBL relay (2) to the TIPM (1). 2. Align the EBL relay terminals with the terminal cavities in the TIPM receptacle and push down firmly on the relay until the terminals are fully seated. 3. Close the TIPM cover. 4. Reconnect the negative battery cable.

SWITCH-REAR WINDOW DEFOGGER