QuestionWe have a 2001 Dodge Durango, the A/C works but only blows thru the defroster, but it wont blow thru the front A?C vents
AnswerHilde,
Your door actuators that open and close the directional doors in the vents work off of a vaccuum system. This system includes the vaccuum source (in your case coming from either the brake booster or intake manifold), a vaccuum harness connector that directs the vaccuum to the specific doors that you request open/close and a series of vaccuum lines to the individual actuators.
By you telling me that it only blows from the defroster vents, that leads me to believe that you have an issue with your source vaccuum. (According to your vaccuum diagram, if all of the lines are receiving no vaccuum (vented) then the default so to speak reverts to the defroster vents. (This is so that if it should go out during the winter, you will still be able to defrost your windshield))
Inside your vaccuum source line, there is a check valve. If it is connected to your brake booster, then it uses the booster's check valve. If it is connected to your intake manifold, it will have its own chack valve. But what I am getting to... a commen fault for these vehicles is that your check valve goes bad or gets stuck open, allowing bleed-through of pressure. This bleeding of pressure drops your vaccuum before it ever reaches your harness connector, so the door actuators never even have a chance to operate.
I would recommend you take it to a reputable shop so that they can hook up a vaccuum pump and confirm this is the fault, and if possible adjust it. Replace if necessary. But they may be able to adjust it so that it consistently pulls the 8 inches of mercury vaccuum that it is supposed to.
Thank you for your question, and I hope that I was of a little assistance. If I can do absolutely anything more now or in the future, do not hesitate to ask. Thank you again, and please remember to rate this answer. Good luck in everything.
