How to: - 2nd Gen NO AC ( or heat) FROM VENTS!!! A "How to" what to look for thread | Ford Explorer Forums - Serious Explorations

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How to: 2nd Gen NO AC ( or heat) FROM VENTS!!! A "How to" what to look for thread

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Turdle

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Here is what to look for if you have a 95-01 with cold ac, and hot heat, but it only blows from the defrost vent.
IF YOU HAVE COLD AND / OR WARM AIR BLOWING FROM DEFROST DUCT ONLY THIS THREAD IS FOR YOU!!!
I will immediately delete all ac cooling questions without answer-let's stay on track with this common issue.
I will also delete all non 95-01 questions
okthankyewverymuch!:D


Let's identify all the parts involved--
First, a picture of the vacuum reservoir

A diagram of the vacuum circuit

then there is the hvac panel of course

Thanks Shamaal for the diagram
VacuumReservoirOrb.jpg


reservoir and lines.jpg


hvac%20diag.gif


ac panel.jpg
 



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Ok, now it is important to understand a bit of how it is supposed to work together-

On the back of the HVAC control is a vacuum switch connection-with several colors of rubber hoses connected to it.
The vent functions are vacuum controlled and powered-there are no cables or wires involved.

Here is the rear of the switch with the plug removed
 

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Vacuum is accumulated in this "globe" or vacuum reservoir

here is a good shot of where it is located, tucked and hidden well in the passenger front wheel well
--see how easy a tire could hit it?
It may look fine, be filled with water (not good) or rattle (not good either) or have broken lines.

For thelowered trucks, or large tire guys-I relocated mine below my cone style open air filter, above the fender liner inside engine compartment. My tire had bumped it.


More info on globe here- http://www.explorerforum.com/forums/showthread.php?t=192337

Here is a thread with several pictures of it, discussing it's location and function

http://www.explorerforum.com/forums/showthread.php?t=169945
 

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There is a vacuum supply line going from the globe to the intake manifold. You should follow it back to be sure it is connected and intact.


The other black line runs to the firewall, to this connector.

It is right above the spot where the radio antenna goes through, in the passenger wheel well area.
It is best to jack up your truck and remove the tire and inner fender liner to get here, as this picture is with the inner fender liner removed. It really only takes 5 minutes at the most to get it off
 

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You'll notice a grey plastic line at this point-it goes to the "coolant bypass valve"
Vacuum is applied at most times, unless ac is selected
at this time the vacuum is switched off to the valve,which in turn cuts flow of coolant through the heater core. This helps the HVAC box run a bit cooler for maximun a/c efficiency

This may develop a vacuum leak-check it

BTW , this is not my truck
 

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Now, going on through the firewall is the "reserve" or " boosted" vaccum.It is the black line.

It arrives through this connector-right above the "fuel pump inertia switch"

The white line is the controlled vacuum return-we'll discuss it later
 

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From there, the black supply line runs here, past a bulk connector
This is on left side of glove box
 

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Then finally, the lines shown connected to rear of HVAC panel-

Sorry for the burry image, but it should be good enough--
 

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Ok, the red blue and yellow line go to no mans land-let's forget them right now.

The white "controlled vacuum" line (from HVAC switch) now goes back through the bulk connector, to the glove box area,through several connections and "T's" to the defrost baffle "motor" (diaphragm)-and back through the firewall for controlled vacuum to the Grey coolant bypass valve line.
Phew!
 

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There you go,
As you can see there are several places to develop a leak-from loose lines hitting the exhaust to a broken globe, or even a leaking contol switch.
Not to mention about 50 connections--
If there is the slightest leak-the diaphragm motor in above post will not "close" and all the air will blow from the defrost ducting--

Now, about the other lines--

The red, blue and yellow lines work to control "blending" of the vents-floor and defrost only. (Don't confuse this with the dreaded hot to cold "blend door")
These colored lines will not usually be a problem--

OK

Your mission, find the vacuum leak.
Mine turned out to be the connection inside the firewall right above the fuel pump inertia switch-it was kicked loose. :confused:

For the first time in over a year, I now have ac from the vents!!!!
 












From there, the black supply line runs here, past a bulk connector
This is on left side of glove box

first off let me thank you for making this thread....ive searched everwhere and the pics you've included really helped. Now these colored tubes I found behind my glove box...my air was working fine until blue tube was cut....could this be the source of my problem? or where my leak is coming from?
 






first off let me thank you for making this thread....ive searched everwhere and the pics you've included really helped. Now these colored tubes I found behind my glove box...my air was working fine until blue tube was cut....could this be the source of my problem? or where my leak is coming from?

definitely. you might be able to just plug it back into the connector, after removing the cut off end--
 






definitely. you might be able to just plug it back into the connector, after removing the cut off end--

thats wat i thought. i had tried that actually and it just sits in the connector now, slipping out every so often. got any idea where I can get another connector and/or a replacement tube?
 






thats wat i thought. i had tried that actually and it just sits in the connector now, slipping out every so often. got any idea where I can get another connector and/or a replacement tube?

There are 2 members here recycling explorers
Both are site vendors

kbabiak
ped5stang

You might send a pm to one of them-
 






There are 2 members here recycling explorers
Both are site vendors

kbabiak
ped5stang

You might send a pm to one of them-

thanks alot man
 












Hello guys i would first like to say how helpful this site is.....Now to the question......My a/c only blows from the defrost ducting on acceleration....what would cause this?
 






Hello guys i would first like to say how helpful this site is.....Now to the question......My a/c only blows from the defrost ducting on acceleration....what would cause this?

I'll bet you have a vacuum leak--
 



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Mine started having this symptom after the battery died on me in winter time... Does this indicate anything?
 






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