To find which fuses in your 1999 Ford Explorer are 7.5 amps, you must consult your owner's manual. The manual has a fuse box diagram that shows the amperage rating for each fuse. You can also often find this information online by searching for "[Year] [Make] [Model] fuse box diagram".
Without your owner's manual or a diagram specific to your vehicle, it's impossible to definitively say which fuses are 7.5 amps. Using the wrong amperage fuse is dangerous and can damage your vehicle's electrical system.