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Hi all,
I have been having an issue when I am accelerating, my vents suck shut and the air goes somewhere else till I let off a little, then I comes back. The ac itself works fine, just loosing my vents, Any thoughts?
Thanks
 

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I have had several Chrysler products from your trucks era. This is a function that was designed into all of then to assist acceleration at wide open throdel. Maybe this function is designed into your truck as well.
Mick
 

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sorry about your a/c

our ram pickups have a vaccum only a/c

the sound of the vent slamming shut is actually closing off your a/c vents and it is going into defroster mode.
put your hands by the defroster vent and you will feel cool air coming out the defroster vents.
you have a vaccum leak(possible) hole in one of your vaccum lines going to your engine.
the a/c accuator box is under your dash next to the gas pedal
on my truck I ziptied the vents permanently so the a/c vent blows air out them all the time.
you will have to do the same thing I did or the only other option is ripping your dash out to install a new actuator box.
I ziptied my actuator box about 3 years ago and no more problems
 

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It could also possibly be a bad in line check valve on the vaccuum line that is in between the engine manifold and the vaccuum accumulator. They are usually a small disk shaped piece that is black on one side and white on the other. It allows the engine to pull vaccuum for the ac controls , but keeps it from escaping back into the manifold under hard accelleration. If you take it out you should be able to blow through one side but not the other. Just a thought and if it is its a cheap easy fix...........DanW
 

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The vents are vacuum operated. When using the "GO" pedal, the vacuum will drop, and the vents will revert to their "rest" state, defrost. Safety feature. In the event if vacuum failure, vents will revert to defrost. Therefore, the windshield will be clear for you to see. You will freeze to death, but you will be safe. When under mild -to heavy load, the vacuum of the motor drops, and there will be a short time when the vents will switch from the selected setting, to defrost. They return back when vacuum rises. If it is chronic, then there may be something more to the problem.
 

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Hey Dirt Dauber -- how do you zip tie those vents open?

sorry about your a/c

our ram pickups have a vaccum only a/c

the sound of the vent slamming shut is actually closing off your a/c vents and it is going into defroster mode.
put your hands by the defroster vent and you will feel cool air coming out the defroster vents.
you have a vaccum leak(possible) hole in one of your vaccum lines going to your engine.
the a/c accuator box is under your dash next to the gas pedal
on my truck I ziptied the vents permanently so the a/c vent blows air out them all the time.
you will have to do the same thing I did or the only other option is ripping your dash out to install a new actuator box.
I ziptied my actuator box about 3 years ago and no more problems


I have a problem with the vacuum tube that controls the vents being broken off very close to the firewall -- can you give me more detail on how you ziptie your vents so the A/C vents blow all the time? This sounds like what I need -- pleaseee- I'm dying from the lack of good A/C.
 

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sorry about your a/c

our ram pickups have a vaccum only a/c

the sound of the vent slamming shut is actually closing off your a/c vents and it is going into defroster mode.
put your hands by the defroster vent and you will feel cool air coming out the defroster vents.
you have a vaccum leak(possible) hole in one of your vaccum lines going to your engine.
the a/c accuator box is under your dash next to the gas pedal
on my truck I ziptied the vents permanently so the a/c vent blows air out them all the time.
you will have to do the same thing I did or the only other option is ripping your dash out to install a new actuator box.
I ziptied my actuator box about 3 years ago and no more problems
It could also possibly be a bad in line check valve on the vaccuum line that is in between the engine manifold and the vaccuum accumulator. They are usually a small disk shaped piece that is black on one side and white on the other. It allows the engine to pull vaccuum for the ac controls , but keeps it from escaping back into the manifold under hard accelleration. If you take it out you should be able to blow through one side but not the other. Just a thought and if it is its a cheap easy fix...........DanW
It's this, I have a 2000 WJ that has the same issue (I'm far too lazy to track it down in a daily that never sees 3000 rpm anymore)
 

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as stated vacuum leak somewhere, though the "Fail Safe" is the defrost setting, as mentioned, this only when occurs, when one has a vacuum leak somewhere.
 

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For my truck I know it's a broke vacuum line -- but it's broken off almost flush with the firewall so I can't splice it to where it broke from very easily.

Does anyone know how to zip-tie the flaps in the "vent" position like that guy Diirt Dauber talked bout?
 
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