* Under the hood in relay boxes: This is the most common location. You'll likely find one or more fuse and relay boxes under the hood, often near the battery. These boxes usually have diagrams on the inside of the lid showing which relay controls what.
* Inside the cab: Some relays, particularly those for less critical functions, might be located inside the cab, perhaps near the fuse box under the dash.
* Behind the glove box: In some models, you might find additional relays tucked away behind the glove box.
To find the specific relay you need:
1. Determine which circuit the relay controls: You'll need to know what you're trying to troubleshoot (e.g., headlights, power windows, fuel pump).
2. Consult your owner's manual: Your owner's manual should have a diagram showing the location of the fuse and relay boxes, and possibly a list of which relay controls what.
3. Use a wiring diagram: A wiring diagram specific to your 1999 Ford F-250 (available online from various sources or through a repair manual) will be the most definitive way to locate the correct relay. These diagrams show the path of the electrical circuits and identify the components, including relays.
Without knowing *which* relay you're looking for, it's impossible to give a precise location. Start by checking the under-hood fuse and relay boxes – that’s the most likely place.
