Ford E350 - Dash vents turn off *FIXED*

This 2012 van came in with the complaint that the air flow out of the vents would stop when accelerating. In reality, it didn't stop but only defaulted to the defrost vents. On a vacuum operated system, the engine pulls a vacuum on a reservoir and it allows the valves to operate normally under low engine vacuum. The check valve closes and seals off the tank until vacuum is restored via the intake manifold. I had quite a time finding the vacuum leak on this van. Join me as we wade into the dashboard of this terrible design and location of the vacuum system.