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

[Turdle]

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

Any other symptoms? Check engine light on?

 

[shamaal]

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?

If it only happens on acceleration look for a problem with the globe. It's function is to 'store' the vacuum for 'release' during acceleration. A common problem is water in the globe from condensation.

 

[Swanny]

Any other symptoms? Check engine light on?

No other symptoms before it went out. Battery died in middle of winter time, when I put a new batt. in, no more front vents.
Ive pretty much gave up on having vents.

 

[DC Larson]

I have a 2000 V8 Merc Mounty. Auto climate control. My air gets cold and hot but when turning fom vents (AC or Fresh Air) to heater it won't come out of the bottem heater vents. When using Vent and Heater mode together, it only comes out the vents. Defrost and heater setting I get defrost only, no heat by my feet. Any idea what may be up?

 

[FexplorerV8]

I just want to add that the A/C "defaults" the air to come out the defrost vents when there is a vacuum leak or a line comes loose as a safety feature, so that if something fails you will still be able to defrost your windshield.

 

[wellston24]

cant find any vaccume leaks

ive looked for hours at all of the vaccume lines and parts that you have stated with no luck at finding anything wrong with them, is there anything else to look at that might help, please

 

[Eplorer]

this thread was awesome ive had this problem now for 2 weeks
and have put it off for more serious problems like my passenger door not opening and my coolant leaking
i finally went to the stealership after i gave up trying to open my door
and asked while i was there abt the AC
they immediately said blend door
and i said that wasnt the problem so he increased the estimate
but now it seems so easy i cant wait to fix it tomorow

is there any was to recognize a leak or any place i should start looking first?

 

[hpfiend]

Great thread thanks for posting this!

A couple of notes from my experience---

1) Bypass the vacuum ball to determine if it is leaking by connecting the black line directly to the source/red line.

2) Go to the firewall vacuum connector behind the glove compartment and switch the black and grey lines temporarily, now connect the grey line to the source and test for functioning-

3) Try to blow or suck through all vacuum lines with vacuum tester or mouth

4) Verify source has vacuum (put thumb over end of red line)

I looked for cracks/leaks for at least an hour with no luck-

However, I couldn't blow or suck through the grey or black lines even with a blow gun on an air compressor-

I finally found out through this testing and some awkward neck angles that the grey line had melted shut due to an extreme heat event below the heater box (probably when my heater box resistor overheated as well) I cut this section of melted line out and patched it with a small section of rubber line-

I then could blow through the grey line- I switched the connector to put it where the black line was and the vents worked but not great because I still had the vacuum ball bypassed...

I figured that the black line had suffered the same "melting" so pulled it forward and backward through the firewall grommet feeling with my fingers until I finally found the disfigured line- I patched it with rubber line as well and then switched all the lines back and hooked up the vacuum reservoir- and tested it before putting the wheel/liner back on...

WORKS LIKE NEW!!!!!

I figured if you could bypass the vacuum ball lines before you went through the rust fighting hassle of removing the inner liner it may save you this work but I never would have been able to access the inside of the firewall grommet had I not removed the liner so I guess it is a necessary evil...

Thanks all for this post and hope this info helps anyone that can't find an obvious vacuum leak before spending money on parts unnecessarily at the dealership.

 

[CDW6212R]

Welcome to the site, and thanks for the ideas. It's the little diagnosing work that saves us a lot of money.

 

[SoCal-RangeR]

Hello All,

I am new to the forum and did some research after reading this thread on my A/C issue.

This is what I have found:

Not sure if I should replace the whole ball or where anything goes to be honest. Any input would help...

What's the name of that black ball? I was told it was a smog ball...

2002 Ford Ranger Edge V6 3.0

 

[hpfiend]

I was told it was called a schwetty ball.

LOL seriously though I believe it is called a vacuum reservoir.

Did you blow through the lines? Is there water in it? Did you try bypassing it to see if it would work?

 

[canardman]

If it only happens on acceleration look for a problem with the globe. It's function is to 'store' the vacuum for 'release' during acceleration. A common problem is water in the globe from condensation.

So, does the globe need to be replaced, or can it be cleaned?

 

[Turdle]

You can remove it and shake the water out. It may take a while, and you will be amazed by the amount which comes out.

or you can find them all over ebay--

http://cgi.ebay.com/ebaymotors/VACU...012QQitemZ220035907377QQrdZ1QQsspagenameZWD1V

 

[canardman]

JT,

I used the picture of "not your truck" Hope you don't mind.... Anyhow, Got under the hood today and traced all of the vacuum lines. came upon this little sensor looking thing. It has 3 lines coming off of the plenum 2 to this sensor and one going to the "vacuum ball" When I pull vacuum from the plenum side, I lose it through the sensor. It lets air through if I use pressure or vacuum. Makes a sound kind of like a bad duck call. I assume this is not correct. What is this sensor, and am I wrong about my assumption?

Thanks, Brent

 

[Turdle]

JT,

I used the picture of "not your truck" Hope you don't mind.... Anyhow, Got under the hood today and traced all of the vacuum lines. came upon this little sensor looking thing. It has 3 lines coming off of the plenum 2 to this sensor and one going to the "vacuum ball" When I pull vacuum from the plenum side, I lose it through the sensor. It lets air through if I use pressure or vacuum. Makes a sound kind of like a bad duck call. I assume this is not correct. What is this sensor, and am I wrong about my assumption?

Thanks, Brent

That there is the EGR vacuum control solenoid-or EGR vacuum regulator.
It is the "vacuum switch " for the egr valve. The PCM sends a signal to it when it wants the EGR valve to open. This signal causes vacuum to be applied to the EGR valve.

 

[canardman]

Nope... still searching.

 

[tarken]

What is the blue box next to is "fuel pump inertia switch"?

 

[CDW6212R]

The air bag module.

 

[tarken]

Tanks!!!!!!!!!!!!!!

 

[evertsen1010]

I'm new anyone know how to fix rear A/C in 1996 Ford Explorer V8 AWD?