Roof will move abt 1 inch from the fully open position then stop. Applying slight persuasion made no difference. When switch is held in close position 12V remained available at motor connections, so apparently there was a physical obstruction somewhere. Had no problem before this happened suddenly abt 4 hrs ago. While checking motor with voltmeter on motor leads, whatever was stuck became unstuck and roof closed normally. Lucky. But what's the cause? Didn't see anything directly applicable in FAQ.

Thanks.