Grand Cherokee 2WD V8-4.7L VIN J (2004)
Power Window Motor: Description and Operation
WINDOW MOTOR
Power operated front and rear door windows are standard equipment on this model. Each door has a permanent magnet reversible electric motor with
an integral right angle gearbox mechanism that operates the window regulator. 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 gearbox housing is secured to the window regulator drum housing with screws. The window regulators used in all four
doors are single vertical post cable-and-drum type. A molded plastic slider guided by the post is driven by the regulator cables. The slider raises and
lowers the window glass through a steel lift plate attachment. Front and rear glass channels within each door guide and stabilize each end of the glass.
The power window motor and gearbox assembly cannot be repaired and, if faulty or damaged, the entire power window motor and gearbox unit must
be replaced. The window regulators are available for service.
A positive and negative battery connection to the two motor terminals will cause the power window motor to rotate in one direction. Reversing the
current through these same two connections will cause the motor to rotate in the opposite direction.
When the power window motor operates, it rotates the regulator cable drum through its gearbox. The window regulator cable drum is connected
through two cables to the plastic slider on the vertical post. As the cable drum rotates, it lets cable out on one side of the drum, and takes cable in on
the other side of the drum. The changes in cable length move the slider up or down the vertical post, raising or lowering the window glass.
If the window regulator or window glass bind, encounter obstructions, or reach their travel limits it overloads the power window motor. The
overloading condition causes the power window motor self-resetting circuit breaker to open, which stops the motor from running.
