Where does this Vacuum Hose go? Pics included
 

I have a 96 blazer. 4.3 vortec v6

Ok, I attached the vacuum hose that you see in pic 1 to a different source of vacuum and I finally got heat through my dash vents (instead of just on my feet and at the window defroster) but that was just a test.

Look at the first pic in the attached files....Anybody know where that hose connects to?

Now look at the second pic in the attached files....It's of the same hose but just a little further down the hose you see a T- Fitting without any hoses connected to the 90 degree connector. Anybody knows where that is supposed to go?

Now here is my theory on how it connects....See pic 3 and tell me if im right or wrong.

Anybody????