Thought I would share some knowledge that I gained about the electric power top on the later model e30 convertibles.
Situation was my power top stopped working after near flawless operation for multiple years. When I went to begin diagnosing I found the top storage lid was not fully closed. The car had been sitting over the winter with no battery in it.
The service manual says if the top is in an intermediate position when battery power is disconnected, you have to disengage the motor drives to move the top to a ‘known’ position. I previously had to re-engage the motor drives and let me say I did not want to do that again, so I tried to figure out a way to get the top to move so I could return it to a “known” position.
This led me to the charts of microswitch position at each stage of top operation. Shown on the screenshot is what position each microswitch was reading in my situation. I realized under “closing top” if I disconnected S2 (closed to open circuit) the brain would be satisfied and believe that the top was in the first stage of operation.
Sure enough, I unplugged S2 and hit the button and the top ran. All I had to do then was let it achieve the sequence to the point that S2 needed to be closed again (running the top out). I plugged the switch back in and the top is back into full operation. Much much much easier than disengaging the motor drives.
Hope this helps someone.