vent issue

[Jimbo]

I'm thinking its a vacuum hose but when i turn on my a/c or well anything that involves air blowing out of my panel vents.. it'll blow for a second then only the hi/floor. Any idea's.. I might have knocked something when i was putting new plugs on the "back" of the engine

 

[02LSE96LSC91SE84TC]

Start with that. Alot of systems use some sort of vacuum canister under the hood to assist with the different vent positions.

 

[Jimbo]

but let me switch it up on ya.. when i stop the car suddenly.. it kicks on then when the car goes still off