RELAY-REAR WINDOW DEFOGGER
DESCRIPTION
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 battery current through a fuse in the power distribution center (PDC) to the rear window defogger grid and to the outside 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 body control module (BCM).
The EBL relay is located in the junction block (JB) in the passenger compartment.
OPERATION
The ISO-standard rear window defogger (EBL) relay is an electromechanical switch that uses a low current input controlled by the body control module (BCM) to control the high current output to the rear window defogger grid lines 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 cannot be repaired and must be replaced if found inoperative or damaged. Refer to the appropriate wiring information for diagnosis and testing of the ISO-standard relay and for complete rear window defogger (EBL) wiring diagrams.
REMOVAL
WARNING: On vehicles equipped with airbags, disable the airbag system before attempting any steering wheel, steering column, or instrument panel component diagnosis or service. Disconnect and isolate the battery negative (ground) cable, then wait two minutes for the airbag system capacitor to discharge before performing further diagnosis or service. This is the only sure way to disable the airbag system. Failure to take the proper precautions could result in an accidental airbag deployment and possible personal injury or death.
1. Disconnect and isolate the negative battery cable.
2. Remove the cover from the junction block (JB) located in the passenger compartment.
NOTE: Refer to the fuse and relay layout map on the inside of the JB cover for EBL relay location.
3. Remove the EBL relay (8) from the JB.
INSTALLATION
NOTE: Refer to the fuse and relay layout map on the inside of the junction block (JB) cover for EBL relay location.
1. Position the EBL relay (8) into the proper receptacle of the JB.
2. Align the EBL relay terminals with the terminal cavities in the JB receptacle and push down firmly on the relay until the terminals are fully seated.
3. Install the cover onto the JB.
4. Reconnect the negative battery cable.