Recently the drivers side dash vent (single vent, left of steering wheel) on my '82 380-SL became inoperable - right side vent and all center vents work correctly - and moving the manual vent slide control control has no effect. Since the other vents work correctly, is each side vent controlled by a separate component of the electronics or could there be some thing wrong with the manual slide control for this vent?

Thanks in advance.

Steve