Question about vacuum operated vent doors.

[CommandoXJ96]

Yes I did search. I keep hearing about vacuum motors that dont work properly in the Heating/A/C system that cuase the system to defualt to the defroster mode. My a/c works, my defroster works, my lower vents work... So im not totally convinced Im faced with a vacuum issue.

The panel vents blow a moderate amount of air but I wish I could get more to come out. I noticed behind the Center (horizontal) panel vent there is a door that never moves in any mode (bi-level, defrost, vent etc... nothing) but all the modes seem to work correctly.

I went ahead and poped the center vent fin assembly out and tried to push back the door Manually - and bingo - huge rush of air - better A/C coming out of all 3 Panel vents then I've ever felt before. Is this door supposed to be stationary? The panel vents work without it pushed back but it seems to be much better when this sucker isnt blocking airflow. I wanna know how to get this guy to open up all the time or at least in the Max or Norm. A/C modes. Anybody have any clue whats up? (hopefully I didnt miss something obvious in my searches)

[Jess]

The vents are controled by vaccum. If you have a leak in the system or a faulty vaccum canister (behind the front bumper on the passenger side) it will cause this problem. Does your cruise control work?

[desertred]

The vents are controled by vaccum. If you have a leak in the system or a faulty vaccum canister (behind the front bumper on the passenger side) it will cause this problem. Does your cruise control work?

My cruise does not work. Is the cruise linked to the cannister behind the front bumper?

I think this has solved my question in another thread where I though my blower moter was operating intermittantly. In fact, the air was just moving to the defrost vents. Stepping on the clutch (manual tranny) will redirect the air flow back to the forward vents (thats the part I can't figure out).

[90xj06]

you have a leak. lack of vacuum during accel

[CommandoXJ96]

my defrost & etc works... which is why im kinda leaning away from the vacuum leaks. I'm just trying to ask if anyone else has actually looked at that vent with the fins removed (you'd need a flashlight also) and knows more about it that'd be great. I spoke with BlackHeep from Naxja who doesnt have any vacuum links who noticed the same thing with the door. It almost feels as if it is Spring Loaded - not vacuum actuated. Maybe I'm crazy.... Does anyone have a link to a diagram of the ductwork/hvac stuff? Or who could contact me and send me one?

Also; I have no cruise control so I'm not sure whether it would work or not. And my airs not going to the defrost vents. (unless of course it is set to defrost)

[CommandoXJ96]

ok... upon further inspection... I found out that somebody disconnected the vacuum purposely on the center and installed a huge worm drive that was supposed to hold the door open wide. talked to my mom - she said a guy at pepboys back in NY 10 years back offered to improve the A/C... my mom didnt know any better; and pepboys aint that great anyways. Go figure. They probably charged her 10 bucks for the worm drive.