"Slow moving" Could the cables be sticking in the sheething like old grease?
Check your getting voltage to the switches.
Not sure how to sync a E34 roof, the E31 I held it in the forward position for like 30 seconds. It made horrible noises and thought my $500 redo was dust but it did work. Never tested it again though. I made sure everything was closed and all windows were up. No clue if that makes a difference.
95 E34 530I V2.37
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Those who make peaceful revolution impossible will make violent revolution inevitable.
John F. Kennedy