oops, I've found an open vacuum connector

[Joda65]

Hi folks,
my 1990 2.3 convertible was coming out of a shop, where they changed the heater core. Now the heater works fine again, but I stumbled over a vacuum connection in the engine compartment that sucks air, but where no vacuum hose is attached. Is there a hose missing, or only a little "dead-cap"?
When I put my finger on the connection, I feel the suction of air, but I feel no other reaction from the engine or whatever by closing or opening this connection with my finger.

Jo


Edit:
Done! Was a missing hose for the defrost flap

 

[broncojunkie]

Does the blend door move when you move the slider? For example, when you move it from floor to vent? Typically, a vacuum leak in that mess of tubing results in blend door issues.