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Why on a 1999 Chevy Astro van does the ac work out of vents only comes out at defrost?
Wiki User
∙ 17y ago
There are two questions. First, MAX AC makes the air colder, usually by recycling the cooled air already in the vehicle. Normal AC pulls fresh air from outside the vehicle into the interior. Second, if your vehicle has an electronic control for the environmentals, you may have a bad control module (inside the section where the knobs are mounted) or the vacuum line may be damaged. Check to see if you can control where the air blows from when using other temperature controls. If you have full control except when you use the MAX AC setting it is more likely the electronic control module is bad.
Wiki User
∙ 17y ago
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...when you turn on your AC in your 1996 Jeep Cherokee and cold air only comes out of defrost and floor vents instead of your main vents. How do you fix?
you need to replace the vacuum.
2002 ford expedition max ac only blows out thru defrost vents?
Check for vacuum leak--either under dash or in engine compartment Check for bad vacuum motors under dash Defrost is the default position for this system There is a vacuum resovoir located behind your battery , it is for this condition. When you accel your engine doesn't produce vacuum due to the throttle plate being open so a resovoir is there to hold a vacuum reserve so that when there is low vacuum produced by the engine there will be reserve to hold the vacuum motor applied preventing the air from changing direction in your dash. When there is no vacuum the direction is at the defrost vents if you have a broken hose or no vacuum your ac would blow out the defrost all the time But since it happens when you accel it sounds like your vacuum resovoir is cracked thus not allowing it to hold a vacuum
What would cause heat not to come out of vents when set to floor and vents?
There are heater doors on the heat blower box that direct the path of the heat. Apparently the heater door to the floor vents is stuck closed.
Why won't the air conditioner in your Jeep blow through the vents?
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Which organisms are the first level consumers at hydrothermal vents?
Shrimp, Giant clams, and Tube worms
Your 2001 Chevy astro van blows air by the defrost vents only any ideas?
You lost the vacuume supply coming from the engine, defrost is the default mode if a mafunction in the vacuume supply is lost.
Your 1999 astro van how do you get the dash board vents to open it stays in the defrost mode how do you fix this?
defrost is the default mode. in most cases a vacuun leak is the culprit.
Where is the air condition duct for the vents on a 1994 Astro van as air only comes out the defrost?
Sounds like a vacuum problem - leak either under hood or under dash -- could ba a bad vacuum motor under dash Defrost is the default position for this system
04 Chevy trailblazer why don't defrost and floor vents work but not face vents?
The mode door actuator has failed. We have instructions for repair at www.trailvoy.com
The air conditioning unit is blowing only through the window defrost vents of 1998 Chevy astro van?
Check the vaccuum hoses going to your manifold- The one that controls air flow direction to your AC is probably split Astroman
Why won't the dash vents work in my 95 Chevy Camaro but floor vent and defrost vent work fine?
the ducts can not be hooked up for the vents to work
Why won't the dash vents work on my 1995 Chevy Camaro but floor vents and defrost vent work fine?
When there is a problem with the vent system it dfaults to the defrost setting. Sounds like you have a problem in the doors that direct the air flow.
Why does Airflow comes out defrost only on olds 98?
It is Likely a vacuum leak under dash leading to vents
...when you turn on your AC in your 1996 Jeep Cherokee and cold air only comes out of defrost and floor vents instead of your main vents. How do you fix?
you need to replace the vacuum.
Where does the vacuum line enter the passenger compartment that controls the AC vents on an 87 Chevy Astro Van?
henry14@yahoo.comh
1991 Chevy G20 van- Why won't airconditioning blow out of dash vents instead of defrost and heat vents?
I had a Chevy van of this vintage and I found a vacum hose leak in the controls that would make the heater/defrost door default too defrost open. lisining carefully under dash or under hood may pinpoint leak. I had a Chevy van of this vintage and I found a vacum hose leak in the controls that would make the heater/defrost door default too defrost open. lisining carefully under dash or under hood may pinpoint leak.
Ac not blowing throw the vents in a 1996 Chevy lumina?
Check the floor heat vent and defrost to see if air comes from them. The vents will be vacuum controlled and a vacuum leak will make the vent doors divert air to the wrong place. Check the entire engine and climate control systems for a vacuum leak.
