Interesting one.
The Antenna was unplugged at the multi pin power plug when we got the car and was in the half up position.
I reconnected it and it went down and refused to come back up....
After I did this, I mistakenly left the plug connected...
The car alarm went off and the battery went flat... several times!
I disconnected the alarm.
Battery still went flat!
Asked a buddy to look at the antenna... and took it out.
Car behaves fine... No battery issues..
I did not figure it out until he tested it and said it worked fine... I put it back in and it still did not go up... I left it connected and just as I was getting frustrated, I touched the body at the top of the plastic housing and it was really HOT!
I tested it with my IR temp sensor...reading was 150deg F...
I took off the power lead again.

Ok, so I took it apart and the electronics at the top are really hot.
I assume that the antenna is not shutting off at the down stop, and the motor and electronics are straining...
That is the reason the battery went flat!

Can it be fixed?
Ideas?

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2009 Mercedes ML320 Bluetec