Rear Window Defogger Relay: Description

WARNING: This page is about a different car, the 2004 Dodge Grand Caravan, 2004 Dodge Caravan, and 2004 Chrysler Town & Country. However, it is still accessible from the selected car via links, so may be relevant.

The rear window defogger relay (Fig 1) is a International Standards Organization (ISO)-type relay. Relays conforming to the ISO specifications have common physical dimensions, current capacities, terminal patterns, and terminal functions. The rear window defogger relay is a electromechanical device that switches battery current through a fuse in the integrated power module (IPM) to the rear window defogger grid and switches battery current through a positive thermal coefficient (PTC) in the IMP to the outside mirror heating grids. The relay is energized when the relay coil is provided a ground path by the rear window defogger relay control in the front control module (FCM).

Fig 1: Identifying Rear Window Defogger Relay

Courtesy of DAIMLERCHRYSLER CORP.

The rear window defogger relay is located in the IPM in the engine compartment. See the fuse and relay layout map on the inner surface of the IPM cover for rear window defogger relay identification and location.

The rear window defogger relay cannot be adjusted or repaired and, if damaged or faulty, it must be replaced.