Ventilations Duct Problem

Hey guys-
When I change between my blower settings (ex floor, floor and face, and defrost) they don't really seem to change and isolate to one setting. It always seems to come out on the floor stronger then the other settings. When I have it on the FLoor/Face setting it comes out with more pressure on the floor. If i just have it on the face, it still comes out with more pressure on the floor. What is the problem here? Thanks

sounds like either a leaking vac hose or a faulty vac module

Where do i find the part at in the car and how much and how easy is it to replace?

The vacuum modulator valve that controls the vent flaps to the ducts is located behind the dash. Before you try to find it start your car and listen closely to see if you can hear a air leak (a quiet hissing sound) while changing the settings form floor to head. The hissing should stop once the vent has changed, if the hissing is constant it is most likely a leak, if it stops it may be the valve itself. It could also be a leak from the main vacuum line under the hood. Like if anyone has recently done work on the engine and left a line off or knocked one off.

I did get my evaporator case drilled cause there was no hole in the bottom of it and everytime i turn the air on it leaked on my passenger floor. I will try to listen for the noise. From my remembering i don't even think there was a noise when i switch them from different settings. If thats the case then whats the promblem? I appreciate the help guys.

If you dont here any noise inside, check for a vacuum leak under the hood. If you still cant find a leak it must be the mod valve but they seldom go bad.

I hate to sound like a dumb*** but where is the vacuum hose under the hood? A picture or good description would help. Sorry about all the questions. I will try to find it as I am waiting for a response.