Check this website: http://www.focusplanet.com/downloads/focusmanuals/2003/2003_focus_owner_guidemanual.pdf
it should be in the fusebox, look in your owners manual if you have it.
In the fuse panel on the driver's end of the dash (visible with driver's door open) in location # 17 is a 20 amp fuse for the cigar lighter/ OBD II.
fuse # 17 is a 20 amp fuse for the cigar lighter , Data Link Connector ( DLC )
# 41 / 20 amp mini fuse / cigar lighter , OBD II diagnostic connector
On the 2003 Ford Explorer - 4 door - in the fuse panel located under the instrument panel on the drivers side , fuse # 24 is a 15 amp fuse for the cigar lighter , OBD II
Your fuse is probably blown. Go buy a pack of new fuses for like $5 dollars.
in the fusebox, look in your owners manual for it's location.
Should be fuse marked F2.12 in fuse box.
I believe it's 39, should say on the inside of the panel that covers your access to the fuse box.
The owners manual list fuse numbers: 1. Power Outlet (Front) 16. Power Outlet (Rear) 31. Cigar Lighter
Were is the cigarette lighter on IST 2003 model?
The fuse is located behind a panel located above the hood release. It is called "socket" on the diagram on the panel. I noted, from the Owner's Manual, that the "cigarette lighter" is actually a 12 V outlet, really not intended for a cigarette lighter.