Before assuming that your car has a defective motor or regulator, a few quick checks are in order. First verify that the fuse or circuit breaker for the windows is OK. Most cars use the same power circuit for all of the windows, so if only one of them isn't working, it's a pretty safe bet that the fuses are OK.
The car we're checking out is a 2002 Pontiac Grand Am 4 door sedan. We'll be looking at the drivers side (left) front window. The cable mechanism used in this vehicle is typical of many late model GM, Ford and Chrysler vehicles as well as most Asian imports. These systems are light weight, extremely adaptable and inexpensive to manufacture making them the system of choice. Unfortunately, high reliability isn't on the top of this list.
Tap the window switch for the bad window and carefully listen for motor noise, etc. in the door. No noise may mean a faulty switch, motor, regulator or wiring. A motor whirring or grinding sounds may indicate a faulty regulator. In either case, we need to pull the door panel and do a little investigative work to be sure of the fault.
