1. Inside the vehicle: Look in your owner's manual. There should be a section dedicated to fuses and relays, which will contain a diagram showing the location of each fuse and its corresponding circuit.
2. On the inside cover of the fuse box itself: The fuse box usually has an inner cover that can be removed (sometimes with a simple pull, other times requiring a small screw). This cover frequently has a diagram printed on it. There are usually two fuse boxes; one under the hood and one inside the vehicle (usually under the dash). The inside one is often the smaller of the two.
If you can't locate it in either of these places, you can also try:
* Online: Search for "2009 Ford F-350 fuse box diagram" on Google Images or a similar search engine. You'll likely find several diagrams from various sources. Make sure the diagram matches your specific trim level (e.g., XL, XLT, Lariat, King Ranch).
* Ford's website: Ford's website might have downloadable owner's manuals or parts diagrams, but finding the specific fuse box diagram can be challenging.
* Your local Ford dealership: A dealership service department can provide you with a diagram.
Remember to always disconnect the negative battery terminal before working with fuses to avoid electrical shocks or damage to your vehicle's electrical system.
