Yes, the Speaker is in the door.
i think you have to unscrew the whole door.
A door panel on a 2004 Mercury Mountaineer is held on by several screws. Once all the screws are removed the panel can easily come off.
They are located in the door latch on the door
Vin the relay panel ,
the four door speakers are 6x8 and the sob if you have one is 8"
spray your door latches with wd40.
Yes, the door panel needs to come off to replace the speaker.
type it in www.google.com
Starting with the 2002 model , there is no automatic transmission fluid dipstick on the Mercury Mountaineer ( and the Ford Explorer , 4 door )
If you do a Google search on Ford Explorer blend door there are lots of articles
( 2 ) There is a fuse panel in the end of the dash on the drivers side ( the plastic fuse panel cover is visible with the drivers door open ) and the Power Distribution Box in the engine compartment on the 1997 to 2001 Mercury Mountaineer