A/C Vent Doors All Close

[dougherp]

Hi Everyone, 06 with auto air. Hot day (above 85) under load, like driving up a long hill the top vent doors will close and stay shut for several miles even after leveling off. Air does not come from dash or defroster vents but will come out of the lower heater vent and the small side vents the direct air to the front driver and passenger windows. I suspect vacuum but don't have a diagram. Any ideas or even better - solutions?

 

[bedrck46]

Look under the hood to see if there is a vacuum diagram it sounds like your loosing vacuum somewhere

 

[bedrck46]

Item Part Number Description
1 18A318 Vacuum control motor — floor/defrost door
2 — Defrost air flow
3 18A478 Floor/defrost door
4 18476 Heater core
5 19860 Evaporator core
6 19805 Blower motor
7 — Outside air inlet
8 19A813 Air inlet door
9 18A318 Vacuum control motor — air inlet door
10 — Recirculated air inlet
11 18B545 Temperature blend door
12 18A559 Panel door
13 — Panel air flow
14 18A318 Vacuum control motor — panel door
15 — Floor air flow
16 — Vacuum from the engine intake manifold
17 19A563 A/C vacuum check valve
18 19A566 Vacuum reservoir tank and bracket
19 19A563 A/C vacuum check valve
20 19B888 ATC solenoid and manifold
21 18495 Heater control valve

 

[dougherp]

Thanks for the reply I'll post when I get to look at it.

 

[dougherp]

Here is what I found - First I found a vacuum hose that had come off - Easy fix.
But while I was looking at all the vacuum hoses I found what seems to be a hard plastic vacuum hose that was not plugged into anything. Does anyone know what it is for and why it is not terminated to anything?
The arrow over my finger is the open end. The arrow to the right is where both vacuum lines come out from a harness wrap. See pic.
Thanks for the reply's.

 

[Webbie]

Talk about a coincidence, ive been trying to find out if that plugs into anything since my A/C front and rear stop working. Driving me nuts not knowing if it plugs into anything

Here is what I found - First I found a vacuum hose that had come off - Easy fix.
But while I was looking at all the vacuum hoses I found what seems to be a hard plastic vacuum hose that was not plugged into anything. Does anyone know what it is for and why it is not terminated to anything?
The arrow over my finger is the open end. The arrow to the right is where both vacuum lines come out from a harness wrap. See pic.
Thanks for the reply's.

 

[Expe2004EB]

I have this exact same problem with my 2004 Expedition. If anyone had this issue could you please share how did you fix it? All help is appreciated!