Low volume from A/C dash vents

I have a 97 Voyager. Recently I noticed that the volume of air
from the dash vents is greatly reduced. When the car was new and the
fan on high, it would come close to frostbite. Now, although the air
is still cold, there is very little volume.
The fan seems to be OK as when it's on heat, there is a definite
difference between the speeds.
Are there vacuum ventilation system duct doors that could be stuck
partially closed? Any idea as to how to correct this?
Thanks in advance

 

Yes. It sounds like a vacuum problem. The default is for the air to
come out the defroster vents, instead of the dash vents. A FSM would
be helpful to track down what door is not getting vacuum.

-KM

 

Do you have a cabin air filter ?? If so have you checked to see if it is
dirty ?

 

Check the recirculation control button, the button next to the air
conditioner button. If it is not on, the air does not blow as hard.
I assume this it to allow the warmer outside air more time to cool.
Try putting the air speed on the third or forth setting and switch the
recirculation on and off and you will notice the difference in air
speed. It takes a few seconds for the air speed to change.

The owner's manual states "Use the recirculation mode to rapidly cool
the inside of the vehicle." If you switch to one of the defrost
modes, the recirculation mode is automatically deactivated. It does
not come back on when you switch back to air conditioning, you must
turn it back on manually.

Also, if you have the rear air conditioning, make sure to keep it on
low, even if you don't have passengers in the back. This will help
the van cool down faster.

One other thing the manual states is "Make sure the air intake,
located directly in front of the windshield, is free of obstructions
such as leaves. Leaves collected in the air intake may reduce airflow
and if they enter the plenum they could plug the water drains."

 

Recirc button actually recirculates inside air back through the a/c..
It turns off the outside air intake and uses cabin air instead.
Thus when in recirc, you are cooling air that was already cooled the
first time it came out of the a/c. That's why it cools faster. Instead
of cooling eg 100° outside air, it recirculates pre-cooled cabin air
at say 90°, which then recirculates to 80°, etc, etc.
I can hear the difference when I engage the recirc button, but the
airflow volume does not change. The noise level just goes up.
There's no rear air on this model.
Thanks for the tip on the air intake, but it's clear. As a previous
poster suggested it's probably a vacuum operated door somewhere in the
system. Guess I'll have to take it to a dealer. I'm not the
contortionist I used to be, to be able to work under a dash.

 

Oh well, thought I had an easy fix for you. I checked mine again, and
when I engage the recirc button I can hear the fan get louder and a
door close under the dash near where the blower fan is. After I hear
the door close the flow of air increases. I understand the part about
needing to be a contortionist to work under the dash. I had to pull
the blower fan a few weeks ago because it was making a noise. I had
sucked in a postit note!