There are several possible culprits, the most likely is the switch assembly in the driver's side door panel. This assembly contains more than switches, though; it also has a printed circuit board that can go bad. The entire assembly, switches and all must be replaced if the circuit board is bad. When mine failed, the driver's side window was entirely inoperative, rather than intermittent, as yours is. I obtained a used replacement switch assembly on E-Bay and that solved the problem. The removal and replacement of the assembly requires that the interior door panel be removed. I ruled out the possibility of a bad electric motor by unplugging it from the switch assembly and applying 12 volts DC (from the battery) directly to the motor plug. The motor puts the window up or down depending on the polarity of the applied voltage. I determined that the switch assembly was bad by measuring the voltage coming into the motor from the switch assembly when the "up" and "down" buttons were pushed. There was no power coming into the motor when the buttons were pushed. Other possibilities include a corroded plug or socket or a break in the wiring where it comes through the frame of the car into the door. You might try opening the door and flexing that wiring while pressing the "up" and "down" buttons. If the window moves at all while you are doing this, the wiring is bad. Good luck. Michael Wilhelm Washington, DC I'm having the same problem, intermitant operation. I first thought it was motor overheat, because I could wait a few minutes and it would operate again, and It seems to stsrt this in cold weather, when I'm running the car heat. Well one day because I had to open my door when it wasn't working, when I closed the door fairly hard (it had me a little irritated!) a the window went down. A little late for my purposes, and I've found out the door shutting doesn't need to rock the car. It may still be a heating problem on the circuit board, but not in the electronic componenets. I suspect a cold solder joint, and plan to look at it again this weekend. I'll let you know.