relocated vac canister, now have HVAC defrost issue

Hey, I think I screwed something up, need help. I recently relocated my vacuum canister ball to put on a bumper, and now I have the HVAC-always-on-defrost problem. I've checked every line I can see and even felt in the firewall line bundle to check where the small hose passes thru the wall, but everything seems OK. No visible cracks, nothing.

If you have the engine idling and pull the hose elbow at the canister, you get this big woosh as the canister de-evacuates, and I can feel the pull of the vacuum if I hold my finger over the line end. I pulled the line at each place and up to the last connection I could feel decent vacuum.

I re-routed my lines when I moved the ball, and now I'm wondering if I left out some important piece, like maybe a check valve or something.

My lines used to look pretty much like this diagram:
http://www.cherokeeforum.com/f2/hvac-controller-vacuum-lines-question-31615/#post359423
except I don't have cruise control so that was just capped off.

When I re-routed I put a white "T" connector on the manifold, one arm has the vac ball line and the other goes across to the HVAC.

This is how I did it at first:



Then I did the old "blow test" (trying to blow thru it - the white "T") and it seemed like the white rubber "T" was valved or something, so I flipped it = the part that is pointed right in the above pic (attached to the heater line) is now on the manifold, and the hole that was on the manifold now has the right-hand heater line in it. That is to say, the ball is one one arm/side of the T, the heater hose is on the other side of the T, and the foot of the T is over the fitting on the manifold. Flipping it didn't help.

This is the only other connector under the hood area:


It appears to be some kind of reducer, cos the line going thru the firewall is smaller than the other line, as you can see.

So, did I leave something important out when I rerouted? Does this routing just not work? SHould I need a check valve in the system somewhere?

I bought a HFT vacuum tester but I dont know how to use it yet. Not sure it would tell me much more anyway. I am at a loss unless the break is way on the other side of the firewall, in the interior compartment, and I don't know how I'd be able to check that....? short of disassembling half of the dash.

Any ideas? I'd really really like to have some AC coming out my main vents this summer!!!!!

Seriously, nobody? Should I move this to OEM tech? I mean, it IS closer to that than to deep mods...

I removed this and pluged the line all works fine , just back track everywhere you worked and see if a hose is loose and go inside on the pass side and see if the hose is on the silver can by the heater box, try moveing the door by hand, hope this helps

Year? On mine, the check valve is between the elbow that plugs into the driver's side of the manifold and the main vacuum line. Don't know if that's your issue, however. Never bothered to see how the HVAC works...

http://s266.photobucket.com/user/AHhub/media/forum stuff/IMG_20120702_191037.jpg.html?sort=3&o=1

There is supposed to be a check valve @ the firewall underneath all the EVAP solenoid junk. This is where the HVAC system's vacuum is sourced. If the valve is backwards you should get the symptoms you've described. If there is no valve you would simply loose HVAC control under hard throttle (low vaccum).

OK, so I added in a generic check valve just before the "T" and it appears the issue may be fixed. I'll update after I've driven it a bit more.