92 300E Door lock vs. Window
 

When I unlock or lock the car from any of the 3 external locks, the driver side window opens from 1 to 3 inches. Once the car is started, I can open the window fully, however, the window will only open fully at one time. I am unable to stop it intermittently. Once the window is fully open, I am unable to close it until I turn the car off, wait 3-4 seconds, turn the key to the on position or start the car. Only then can I close the window. I have found the Convenience control modual and believe this could be the problem. However, I do not want to spend approximately $300 to test my theory. Any suggestions will be greatly appreciated.