Hello everyone! 1995 Olds 98. Blowing through the central deflectors disappears while driving. Blowing appears again after some time, but then disappears. I checked all the vacuum lines, checked the vacuum manifold and the vacuum valve - everything is fine. I can't understand what is the reason? When starting the car, the air conditioner blows normally, but after driving a couple of kilometers, the blowing stops. What could be the problem?