Re: 2003 Explorer - 12v source for accessories
There should be two fuse panels, one under the hood (check for spare fuse/port not being used) and a smaller fuse panel under the dash (drivers area). As jwko mentioned, if you're going to be running more than 20amps regularly it's not advisable to use a fuse, run it straight from the battery. The majority of 12V sockets will handle up to 20amps. If you want to hard wire it and don't use the cig lighter, you can splice into the wiring behind the dash and use that connection for the radio. If you do, I would make sure that the current draw is not greater than 5amps just to be safe in overheating the wiring.
Don't forget that emergency vehicles are specified before they leave the factory, so they are built a bit differently with some extra options & deletions.
'11 Ram Quad Cab 4x4 SXT 5.7L HEMI (stock); 48,500m
'06 Pontiac G6 GT 3.5L 220hp; 64,000m
'12 Chrysler 200 Limited 3.6L 283hp; 28,000m
'99 Taurus 3.0L 2V Vulcan 145hp; 154,300m - Traded
Amsoil in all vehicles!