I finally got around to fixing it. I called Northern Breeze to order parts. They weren't free. Usually there is a gear part that fails. After I ordered the part, I took it apart and discovered the gear part has become unscrewed from the vent, causing it to be inoperable. I dipped both screws in blue lock-tite and screwed them back in. Works like a charm. If your vent line starts to act up, take it apart and start looking for the gear part (I think it is called transporter) to check if in came unscrewed.
Jim & Sherri
02 Winnebago Sightseer 27c Class A;
"Scout" Springer Spaniel