Jeep Cherokee (XJ): Description and operation

Power window switch

The individual power windows are controlled by a two-way momentary switch mounted on the trim panel of the passenger side front door trim panel and, on four-door models, on each of the rear door trim panels. Two-way momentary master switches on the driver side front door trim panel control all of the power windows in the vehicle. The driver side front door trim panel also has a two-position power window lockout switch.

The front door power window switches and the power window lockout switch are integral to the Driver Door Module (DDM) or Passenger Door Module (PDM), respectively. The rear door power window switches are stand-alone units.

Each power window switch controls its power window motor by switching battery current and ground between the terminals of the power window motor.

The passenger side front door and, on four-door models, both rear door power window switches receive their battery feed through the power window lockout switch or through the master switches in the DDM.

Also, each of the individual power window switches receives its ground through the DDM. When the lockout switch is placed in the Lock position, the individual power window switches become inoperative because they have no battery current available to them. However, the master switches are unaffected by the lockout switch position.

Each power window switch, except the lockout switch, is illuminated by a Light-Emitting Diode (LED) when the ignition switch is turned to the On position. However, when the power window lockout switch is placed in the Lock position, the LED for the locked-out passenger side front and, on four-door models, the rear passenger door power window switches is turned off.

The front door power window switches and their lamps cannot be repaired and, if faulty or damaged, the entire door module must be replaced. The rear door power window switches and their lamps cannot be repaired but, if faulty or damaged, only the affected switch unit must be replaced.

Door module

A Driver Door Module (DDM) and a Passenger Door Module (PDM) are used on all models equipped with power locks and power windows. Each door module houses both the front door power lock and power window switches. In addition to the switches for its own door, the DDM houses individual switches for each passenger door power window, a power window lockout switch, the power mirror switch, and circuitry to support the one-touch down feature of the driver side front door power window. The PDM also houses the control circuitry and the power lock and unlock relays for the power lock system.

The DDM and the PDM are mounted to their respective front door trim panels. The DDM and PDM are serviced individually and cannot be repaired. If the DDM or PDM, or any of the switches and circuitry that they contain are faulty or damaged, the complete DDM or PDM unit must be replaced.

Power window motor

A permanent magnet reversible motor moves the window regulator through an integral gearbox mechanism.

A positive and negative battery connection to the two motor terminals will cause the motor to rotate in one direction. Reversing the current through these same two connections will cause the motor to rotate in the opposite direction.

In addition, each power window motor is equipped with an integral self-resetting circuit breaker to protect the motor from overloads. The power window motor and gearbox assembly cannot be repaired and, if faulty or damaged, the entire power window regulator assembly must be replaced.

Circuit breaker

An automatic resetting circuit breaker in the junction block is used to protect the power window system circuit. The circuit breaker can protect the system from a short circuit, or from an overload condition caused by an obstructed or stuck window glass or regulator.

The circuit breaker cannot be repaired and, if faulty, it must be replaced.