Look under the vehicle and count them.
the four door speakers are 6x8 and the sob if you have one is 8"
( 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
There are seat belts for ( 5 ) people
The check " gage " light on in your 1997 Mercury Mountaineer indicates that either your engine oil pressure is LOW , your engine temperature is HIGH or your gas tank is AT OR NEAR EMPTY .
According to the 1997 Mercury Mountaineer owners manual : Your 4R70W automatic transmission capacity is ( 13.9 quarts ) * that of couse would be for the transmission , torque converter , lines , transmission cooler , etcetera *
There are two head gaskets in the V 8 1999 mercury mountaineer
According to the 2004 Mercury Mountaineer Owner Guide : ( 22.5 U.S. gallons )
According to the 2007 Mercury Mountaineer Owner Guide : ( there are 5 lug nuts per wheel )
According to the 2007 Mercury Mountaineer Owner Guide : ( the fuel tank capacity is 22.5 U.S. gallons )