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Mike Giddens
Mike Giddens, Ford Master Certified
Category: Ford
Satisfied Customers: 70
Experience:  Over 14 years experience, Ford Master Certified in Chassis Repair, Sync System, Hybrid
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2004 Explorer: I recently changed..blend door..cold air at all vents

Customer Question

My 2004 Explorer has plenty of heat at the floorboards but no heat at mid-level or defroster. I recently changed out the blend door and actuator so I know that's not the problem. All the pneumatic actuators move when you select the different heat (defrost, floor, mid) but I still only get cold air at all vents but the floor. I have checked all the vacuum lines and all the doors seem to be working properly.
Submitted: 7 years ago.
Category: Ford
Expert:  Mike Giddens replied 7 years ago.
Hi, my name is XXXXX XXXXX let me see if I can help you. a couple of questions: 1. Which blend door and actuator did you replace? 2. Does this unit have automatic or manual ac? Do you have good airflow from all vents in all modes?
Customer: replied 7 years ago.
I replaced the primary blend door and blend door actuator about 6 months ago. The door is working fine still and had heat from all vents until about a week ago but now we only get heat from the floorboards. It has manual AC. Great airflow from all vents when I select each "zone". All vacuum lines are connected and I can see or hear each door open and close when I select each zone I currently have half the dash removed).
Expert:  Mike Giddens replied 7 years ago.

graphicIs this the blend door actuator you changed #5?





Customer: replied 7 years ago.
Yes, it sure is. I purchased an aftermarket blend door (metal) from heater-treater and installed that at the same time. The aftermarket door has a metal arm and bolt on the receiving end (passenger side) and I can see the arm moving freely as I chance the temperature so I know that it's working fine.
Expert:  Mike Giddens replied 7 years ago.

Look at the plenum chamber on top of the evaporator case. Take a close look at all of the actuators for movement and make sure that none of them are broken. The vacuum actuators will still move in and out but if they are broken off of the connectors, they won't open the doors. Bare with me I am just trying to figure this out with my schematics.

Customer: replied 7 years ago.
All the connectors on the actuators are fine. Where is the Plenum exactly?
Expert:  Mike Giddens replied 7 years ago.

The plenum sits on top of the evaporator case right in the center of the dash behind the radio and ac control head. #6. I went back and looked through the blend door operation diagram and everything you are describing, including the actual pinpoint test, points to the temperature blend door actuator. If you want I could send the diagram then you can see how the air flow operates in this system. Let me know.



Customer: replied 7 years ago.
If you could send that diagram it would be appreciated. I plan to remove the metal bar on the receiving end tof the belend door (pass side) that has the bracket that I mentioned to you, The arm that is attached to the receiving side may not be allowing the door to make a free swing as is it causes a stop point, something that the OEM doesn't have

Expert:  Mike Giddens replied 7 years ago.




This is the air disribution schematic I was talking about. Numeber 8 being the temperature blend door. Yes check that door closely to see if it is binding. That would not allow your heat to come through.



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Customer: replied 7 years ago.
I also traced the HVAC system and drew the conclusion that the only possibility could be the Blend door. The aftermarket one that I installed had a lever on the receiving side (passenger side) where it came through the ducting. Well the problem was that it was acting like a stop and determining how far the door could open, I removed the arm and it now works like a champ. Thanks for the help and happy holidays!
Expert:  Mike Giddens replied 7 years ago.
I am so glad I could help you. If you need anymore help please contact me and Happy Holidays to you.