weak air flow out of vent?

[Steve Grchan]

The floor setting works great in all blower setting (low through high) but the defrost isnt the greatest and the main vents hardly nothing on high. I have checked all vac lines under hood which are fine and i have a new blower motor( and its the correct rotation). Theres a door behind the glove box that i think uses cabin air and it works and theres another one i can see next to the gas peddle that also moves. I can hear the motor running hard like alot of air is going somewhere just dont feel anything on all motor speed when selected to the vent that blow on you. Kinda stuck at this point? 1999 2wd

[Steve Grchan]

Does the floor vents go through the evaporator also because it works great in all blower speeds? I have a vacuum gauge i just purchased and im going to compare the vac between the hood and in side of cab.

[MnTom]

Far as I know all vents go through the evaporator. This sounds like a door is not moving to the correct position.

[Steve Grchan]

I had some of my wonderful dash fall down in there could ot be possible it might have jammed something up? And i will check the selector and see what i can find there.

[Mopar1973Man]

Here is the box opened up...

[Hawkez]

If you can find something on this please share with the rest of us.  I am experiencing something similar, although mine seems to be intermittant.  The fan is turning but almost no air flow out of the vents.  A month or two ago I pulled my fan to see if debree was plugging any of the ducting.  I did find a handful of garbage in the fan, but nothing that I would have thought could block off air flow.  I couple of times during these moments of bad air flow I have smelled something burning, not an electrical smell but more of a paper smell.  I looked all over trying to find leaves that may have got hot and had fumes seep into the air circulation. 

 

One thing that I have found is if I cycle my vent selector my issue will usually clear up and work as advertised.  Good luck, I hope you figure yours out.

[Steve Grchan]

Thanks, i am going to verify my vacuum is good at the servos and does anyone know if i need to check vacuum at the selector? I also had leaves in mine. I put my hands up in where the blower motor is and its pretty dirty. So i will be pulling it apart and giving everything a good cleaning and im thinking of putting a new heater core and evaporator in while i have it apart. Since my dash is gone i do feel some air blowing around the center vents in the dash. Is there a seal on the casing that may have withered away? I have some foam like material that has blown out some of the vents.

[Steve Grchan]

Mopar thank you for the picture and this great site!

[MnTom]

If the vacuum system was not producing enough vacuum the whole HVAC system would 'default' to defrosters only. You can pull the hoses at each vacuum motor and see if you have suction.

[banzaitoyota]

www.heatertreater.net

[Hawkez]

www.heatertreater.net

Does anyone have experience with this product?

[Mopar1973Man]

Heater treater is for the blend door on the heater core.

 

i am going to verify my vacuum is good at the servos and does anyone know if i need to check vacuum at the selector?

 

If the vacuum system was not producing enough vacuum the whole HVAC system would 'default' to defrosters only.

 

Correct if the vacuum is too weak or nothing at all you get DEFroster only.
 

 

I also had leaves in mine. I put my hands up in where the blower motor is and its pretty dirty.

 

Most likely what happen is the A/C evaporator is plugged with dirt. Common issue where the evaporator sweats and travel dirt roads and presto a caked up brick. If you replace it make sure to use only MAX A/C if in dusty areas.
 

 

Is there a seal on the casing that may have withered away?

 

No. Just plastic to plastic seal.

 

I have some foam like material that has blown out some of the vents.

 

It could be from the vent doors which are covered with a sealing foam or the sealing foam around the evaporator.