Probable Vacuum Leak on A/C Recirc Door?

[dlyoung1]

Happy Friday! My wife's 2003 Expy has a small problem in the a/c that I need a little help with. When you set the a/c control to MAX, the air flow through the dash vents works just fine at idle, but as soon as you hit the throttle, the blend door eases closed and the air diverts to the defrost vents. Sounds like classic vac leak. But it's ONLY in the MAX/RECIRC position.

Found a vacuum diagram for the vehicle and it shows the recirc door actuator on its own "branch" off of the a/c control panel vacuum. I'm thinking there must be a leak/break/loose connector in that branch. Question: Where do I start looking for that recirc actuator?

Thanks!

 

[Hamfisted]

How's the vacuum line coming off the intake manifold? That elbow on the front corner (driver's side) is notorious for leaking with age.
The HVAC air inlet vacuum actuator is buried behind the glovebox & blower. White vacuum line attached to it.
The O-rings in the distribution manifold are known to leak after many years too.


Manual AC vacuum diagram.

Port Hose Color Function
1 White Air Inlet Door
2 Blue Floor/Defrost Door
3 Black Vacuum Source
4 Yellow Floor/Defrost Door
5 Red Panel Door
6 Orange Panel Door




Vacuum Application Chart — Manual A/C
Switch Port Color Function Function Selector Switch Position
MAX A/C PANEL PNL/ FLR OFF FLOOR FLR/ DEF DEF
1 White Recirc/ Fresh V NV NV V NV NV NV
2 Blue Floor/ Defrost NV V V NV V V NV
3 Black Vacuum Source V V V V V V V
4 Yellow Floor/ Defrost NV V V NV V NV NV
5 Red Panel V V V NV NV NV NV
6 Orange Panel V V NV NV NV NV NV

V = Vacuum
NV = No Vacuum

 

[dlyoung1]

Ham: Thanks for the vac system diagram! Allow me to walk through what I think I'm looking at, just for clarity.
- Recirc Door actuator is @9, the door itself @8
- Floor/Defrost actuator is @1, with dual vac inputs
- Panel Vents actuator is @14, with dual vac inputs

Question: On the diagram what is the fresh air source entering the air box through the door and actuator @21 "T-ed" off of the white Recirc Door line?