I BELIEVE that ( fuse #21 ) is a 15 amp fuse for the hazard flashers on your 1998 Ford Explorer Sport ( at least it is on the 1998 Ford Explorer four door )
# 17 is a 20 amp fuse for the cigarette lighter and Data Link Connector in a 2001 Ford Explorer Sport
On your 2001 Ford Explorer Sport Trac fuse # 1 is a 5 amp fuse for your power mirror switch
where is the fuses for the factory amp in a 1998 ford expedition
in cargo area behind plastic cover hidding the speaker,
There is no owners manual shown for a 2004 Ford Explorer Sport on Fords website The 2004 Ford Explorer owners manual shows ( fuse # 24 - 15 amp - cigar lighter , OBD II , neutral tow ) The 2004 Ford Explorer Sport Trac which has the fuse panel on the drivers end of the dash where the fuse panel cover is visible with the drivers door open shows ( fuse # 17 - 20 amp - cigar lighter , OBD II )
On a 2005 Ford Explorer Sport Trac : In the Power Distribution Box ( which is " live " ) located in the engine compartment ( # 30 is a 20 amp mini fuse for the fuel pump )
It came from the factory with a 650 cold cranking amp battery
On a 1998 Ford Explorer , fuse # 18 , 25 amp , is for the drivers unlock relay , all unlock relay , and all lock relay
On a 1999 Explorer there is a 7.5 amp fuse in location # 10 of the fuse panel for the overhead console.
The factory amp is mounted in the cargo compartment, inside the rear hatch on the immediate left. It is directly across from the jack and lug wrench compartment.
# 25 is a 7.5 amp fuse for the speedometer , GEM system on a 1996 Ford Explorer ( in the fuse panel in the end of the dash , the fuse panel cover is visible with the drivers door open )