To find it, you'll need to consult your owner's manual. It will have a diagram showing the fuse box layouts (there's usually more than one) and a legend indicating which fuse controls the wipers.
If you don't have the owner's manual, you can often find a downloadable PDF version online through Ford's website or a reputable automotive repair manual provider. Searching for "1998 Ford E350 owner's manual PDF" should yield results.
In general, you should look in these potential locations:
* Under the hood: This is the most common location for fuse boxes.
* Inside the cab: Often found under the dashboard, sometimes near the steering column or the driver's side.
Remember to turn off the ignition before checking any fuses. And use a flashlight to help illuminate the fuse box.