The change of seasons sometimes reveals problems with a vehicle that might otherwise go unnoticed. If you have a Jeep Grand Cherokee or Ford Explorer that has an outside air leak behind the glove box, you may have a broken fresh air door (also known as a recirculation door or Max door). The fresh air door is used to recirculate air in the passenger compartment or allow fresh air into the HVAC (Heating, Ventilation, and Air Conditioning) system. Surprisingly, the Explorer and Grand Cherokee share a common defect in the heating and air conditioning system. Fresh air doors are made of weak plastic which can often break under the stress of the control actuator. When it’s cold outside, this problem becomes very apparent. In hotter climates during the summer, a broken fresh air door drastically reduces the efficiency of the air conditioner.
checking it out it’s easy by operating the fresh air door and listening for increased airflow. When the climate control setting is moved to the maximum, the sound of air blowing through the vents should be louder because the fresh air door is sealing in outside air, forcing inside air to recirculate. If the sound is not louder, you can open the glove box door and look behind to see if the door works by changing the setting from normal to maximum. If the door doesn’t move visibly, it’s probably broken. Sometimes the door can even drop to the bottom of the box, positioned just above the blower. It may not be visible, sometimes you can stick your fingers through the plastic grille and feel the door is loose at the bottom.
Replacement of the door is not a DIY job. Dash must be turned out and HVAC box removed on Grand Cherokees. On Ford Explorers, the work can be done without removing the casing, but the assembly must be replaced. Obviously, if the casing needs to be removed, the coolant must be recovered, which requires an AC machine. So if you are mechanically inclined, the one to do at home might be the Explorer, of course this depends on your mechanical ability. Even if you are not going to be doing this job yourself, this information can be used to help explain to the repair shop what the problem is. By providing more information to get the technician to the problem area, diagnostic time can be reduced.
