I have a code for a window limit switch on the Lt. door I understand the switch is in the motor and assume it must tell the computer the direction of rotation and revolutions. “I know what happens when you assume” Anyway how can I test the motor or sensor in the motor and see if it is working correctly or not. I was thinking of using a multi channel scope to see what I could see but I am still not sure how this switch can tell the computer the window is up or down. Second I know this code will keep the top from going all the way up because it thinks the window is still up. Will it also keep the unlock mechanism in the windshield post for unlocking? Also when you open and close the same door the window will not lower its self like it should

You don't mention the model and year but I'll "assume" it's an early 129. If so, it does indeed have limit switches in the doors(not the motors) to signal the soft-top ECU when the windows are all the way down. Later 129's use hall-effect type sensors to determine window position. If you've got a limit switch problem you're lucky. Cheap and easy.

Its a 1997 500sl sorry about that i belive it has the hall effect sensor. Do you know how I can test it if that is what i have?

Well I found the problem, it is an hall effect system and the brown and yellow wire send a signal back to the computer letting it know when the motor is rotating, which direction and I am sure the computer is counting revolutions also. Using a scope I watched the pattern and found the brown wire was not putting out any signal. Order a new motor and we will go from there.