* Under the hood in the fuse/relay box: This is the most common location. The fuse/relay box is typically located near the battery, often on the driver's side fender well. The relay itself might be labeled, or you may need to consult a wiring diagram (available online or through a repair manual) to identify it.
* Inside the passenger compartment fuse box: Less common but possible on some models. Again, a wiring diagram will be crucial to locate it if this is the case.
To find it:
1. Consult a wiring diagram: This is the most reliable method. You can find wiring diagrams online (though accuracy varies) or purchase a Haynes or Chilton repair manual for your specific year and model. The diagram will show you the relay's location and often its designation.
2. Check the fuse box under the hood: Systematically examine each relay in the box. Some relays may be clearly labeled. If you find a relay that's noticeably larger or different than the others, it *might* be the fuel pump relay (but don't assume).
3. Listen for the fuel pump: With the key in the "on" position (but not cranking the engine), listen carefully near the fuel tank. If you hear a brief whirring sound, that's the fuel pump priming. Then try removing relays one by one (make a note of their position!) to see which one stops the whirring sound. Be extremely careful not to short anything when doing this. This method is risky if you're unsure of what you're doing.
Important Considerations:
* Safety First: Always disconnect the negative battery terminal before working with any electrical components.
* Use a wiring diagram: Guessing is not recommended. Using a diagram will minimize the risk of damaging your vehicle.
* Professional help: If you are uncomfortable working with car electrical systems, it's best to take your Bronco to a qualified mechanic. Incorrectly identifying or replacing the relay could lead to further problems.
