Testing Convenience Control Unit
 

I have a 92 500e and have 2 issues with the Convenience Control Unit. First is that it won't close anything nor open the windows when using the key in the door/trunk locks. The second issue is that the front passenger side window goes down all the way and won't come back up. This has lead me down the testing path from the benz manual and everything seems to be meeting the values expected. I tested the motor independently and it work both up and down. When control unit activated it is sending a constant 12V to the window motor. When the up switch is pressed, it drops slightly. When I put the motor up using external 12v, there was not problem until I touched the window switch at which time it went down immediatly.

The end of the trouble shooting leads to a "Control Unit Faulty" cause. I

s there any way to test the control unit?

Thanks,
Lee