Behind right side of dash, top of A/C plenum. If you open the glovebox and lower it by pushing in the two tabs on the side you will be able to see it.
Its the blend door. It happened on my 98 Mercury Mountaineer. The motor shaft and the door have separated there is an easy fix look up blend door fix for 98 Mercury Mountaineer it just needs a small finishing nail and done
If you do a Google search on Ford Explorer blend door there are lots of articles
the blend door actuater is bad
Mercury Mountaineers have a "blend" door in the heater box. It is probably malfunctioning. You can find more info by searching for Ford + "blend door" or "no Heat"
In a 1998 Mercury Mountaineer, the blend door is located within the HVAC system, typically behind the dashboard. To access it, you often need to remove the dashboard and some interior panels to reach the climate control assembly. The blend door regulates the mixture of hot and cold air, allowing for temperature adjustments in the cabin. If you're experiencing issues with heating or cooling, it may be worth checking the blend door actuator as well.
There are seat belts for ( 5 ) people
I believe you are looking for blend door actuator???
How to take the door panel off a 2002 mercury mountaineer?
its your blend door failed or your blend door actuator failed. 1 of the 2 or both. cant find any info on tearing out dash in 03 mountaineer and it appears to me that my research says its in a different spot than other years.
On a 2001 Mercury Mountaineer : Underneath the Mountaineer , below the drivers door , mounted on the frame rail
They are located in the door latch on the door
the four door speakers are 6x8 and the sob if you have one is 8"